Browsing by Author "Infante, Leopoldo"
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- ItemDesign for the First Narrowband Filter for the Dark Energy Camera: Optimizing the LAGER Survey for z ∼ 7 Galaxies(2019) Zheng, Zhen-Ya; Rhoads, James E.; Wang, Jun-Xian; Malhotra, Sangeeta; Walker, Alistair; Mooney, Thomas; Jiang, Chunyan; Hu, Weida; Hibon, Pascale; Jiang, Linhua; Infante, Leopoldo; Barrientos, L. Felipe; Galaz, Gaspar; Valdes, Francisco; Wester, William; Yang, Huan; Coughlin, Alicia; Harish, Santosh; Kang, Wenyong; Khostovan, Ali Ahmad; Kong, Xu; Perez, Lucia A.; Pharo, John; Wold, Isak; Zheng, XianZhongWe present the design for the first narrowband filter, NB964, for the Dark Energy Camera (DECam), which is operated on the 4-m Blanco Telescope at the Cerro Tololo Inter-American Observatory. The NB964 filter profile is essentially defined by maximizing the power of searching for Lyman-alpha emitting galaxies (LAEs) in the epoch of reionization, with the consideration of the night sky background in the near-infrared and the DECam quantum efficiency. The NB964 filter was manufactured by Materion in 2015. It has a central wavelength of 964.2 nm and a full width at half maximum (FWHM) of 9.2 nm. An NB964 survey named Lyman Alpha Galaxies in the Epoch of Reionization (LAGER) has been ongoing since December 2015. Here, we report results of lab tests, on-site tests, and observations with the NB964 filter. The excellent performances of this filter ensure that the LAGER project is able to detect LAEs at z similar to 7 with a high efficiency.
- ItemDynamical versus stellar masses of ultracompact dwarf galaxies in the Fornax cluster☆(2011) Chilingarian, Igor V.; Mieske, Steffen; Hilker, Michael; Infante, LeopoldoThe origin of ultracompact dwarf (UCD) galaxies, compact extragalactic stellar systems, is still a puzzle for present galaxy formation models. We present the comprehensive analysis of high-resolution multi-object spectroscopic data for a sample of 24 Fornax cluster UCDs obtained with VLT with Fibre Large Array Multi Element Spectrograph (FLAMES). It comprises previously published data for 19 objects which we re-analysed, including 13 with available Hubble Space Telescope (HST) photometric data. Using Virtual Observatory technologies we found archival HST images for two more UCDs and then determined their structural properties. For all objects we derived internal velocity dispersions, stellar population parameters and stellar mass-to-light ratios (M/L)(*) by fitting individual simple stellar population (SSP) synthetic spectra convolved with a Gaussian against the observed spectra using the NBursts full spectral fitting technique. For 14 objects we estimated dynamical masses suggesting no dark matter (DM) in 12 of them and no more than 40 per cent DM mass fraction in the remaining two, in contrast to findings for several UCDs in the Virgo cluster. Some Fornax UCDs even have too high values of (M/L)(*) estimated using the Kroupa stellar initial mass function (IMF) resulting in negative formally computed DM mass fractions. The objects with too high (M/L)(*) ratios compared to the dynamical ones have relatively short dynamical relaxation time-scales, close to the Hubble time or below. We therefore suggest that their lower dynamical ratios (M/L)(dyn) are caused by low-mass star depletion due to dynamical evolution. Overall, the observed UCD characteristics suggest at least two formation channels: tidal threshing of nucleated dwarf galaxies for massive UCDs (similar or equal to 108 M-circle dot), and a classical scenario of red globular cluster formation for lower-mass UCDs (less than or similar to 107 M-circle dot).
- ItemLAGER Lyα Luminosity Function at z ∼ 7: Implications for Reionization(2022) Wold, Isak G. B. ; Malhotra, Sangeeta ; Rhoads, James ; Wang, Junxian ; Hu, Weida ; Perez, Lucia A. ; Zheng, Zhen-Ya ; Khostovan, Ali Ahmad ; Walker, Alistair R. ; Barrientos, L. Felipe ; González-López, Jorge ; Harish, Santosh ; Infante, Leopoldo ; Jiang, Chunyan ; Pharo, John ; Moya-Sierralta, Cristóbal ; Bauer, Franz E. ; Galaz, Gaspar ; Valdes, Francisco ; Yang, HuanWe present a new measurement of the Ly alpha luminosity function (LF) at redshift z = 6.9, finding moderate evolution from z = 5.7 that is consistent with a fully or largely ionized z similar to 7 intergalactic medium. Our result is based on four fields of the LAGER (Lyman Alpha Galaxies in the Epoch of Reionization) project. Our survey volume of 6.1 x 10(6) Mpc(3) is double that of the next largest z similar to 7 survey. We combine two new LAGER fields (WIDE12 and GAMA15A) with two previously reported LAGER fields (COSMOS and CDFS). In the new fields, we identify N = 95 new z = 6.9 Ly alpha emitter (LAEs) candidates, characterize our survey's completeness and reliability, and compute Ly alpha LFs. The best-fit Schechter LF parameters for all four LAGER fields are in good general agreement. Two fields (COSMOS and WIDE12) show evidence for a bright-end excess above the Schechter function fit. We find that the Ly alpha luminosity density declines at the same rate as the UV continuum LF from z = 5.7 to 6.9. This is consistent with an intergalactic medium that was fully ionized as early as redshift z similar to 7 or with a volume-averaged neutral hydrogen fraction of x (H I) < 0.33 at 1 sigma.
- ItemLyα emission-line galaxies at z=3.1 in the extended Chandra Deep Field-South(2007) Gronwall, Caryl; Ciardullo, Robin; Hickey, Thomas; Gawiser, Eric; Feldmeier, John J.; van Dokkum, Pieter G.; Urry, C. Megan; Herrera, David; Lehmer, Bret D.; Infante, Leopoldo; Orsi, Alvaro; Marchesini, Danilo; Blanc, Guillermo A.; Francke, Harold; Lira, Paulina; Treister, EzequielWe describe the results of an extremely deep, 0.28 deg(2) survey for z = 3.1 Ly alpha emission-line galaxies in the Extended Chandra Deep Field-South. By using a narrowband 5000 angstrom filter and complementary broadband photometry from the MUSYC survey, we identify a statistically complete sample of 162 galaxies with monochromatic fluxes brighter than 1.5 x10(-17) ergs cm(-2) s(-1) and observer's frame equivalent widths greater than 80 angstrom. We show that the equivalent width distribution of these objects follows an exponential with a rest-frame scale length of w(0) = 76(-8)(+11) angstrom In addition, we show that in the emission line, the luminosity function of Ly alpha galaxies has a faint-end power-law slope of -1.49(-0.34)(+0.45) a bright-end cutoff of log L-* = 42.64(-0.15)(,)(+0.26) and a space density above our detection thresholds of (1.46 +/- 0.12); 10(-3) h(70)(3) galaxies Mpc(-3). Finally, by comparing the emission-line and continuum properties of the Ly alpha emitters, we show that the star formation rates derived from Ly alpha are similar to 3 times lower than those inferred from the rest-frame UV continuum. We use this offset to deduce the existence of a small amount of internal extinction within the host galaxies. This extinction, coupled with the lack of extremely high equivalent width emitters, argues that these galaxies are not primordial Population III objects, although they are young and relatively chemically unevolved.
- ItemLyα-emitting galaxies at z=3.1(2007) Gawiser, Eric; Francke, Harold; Lai, Kamson; Schawinski, Kevin; Gronwall, Caryl; Ciardullo, Robin; Quadri, Ryan; Orsi, Alvaro; Barrientos, Felipe; Blanc, Guillermo A.; Fazio, Giovanni; Feldmeier, John J.; Huang, Jia-Sheng; Infante, Leopoldo; Lira, Paulina; Padilla, Nelson; Taylor, Edward N.; Treister, Ezequiel; Urry, C. Megan; Van Dokkum, Pieter G.; Virani, Shanil N.We studied the clustering properties and multiwavelength spectral energy distributions of a complete sample of 162 Ly alpha- emitting (LAE) galaxies at z similar or equal to 3: 1 discovered in deep narrowband MUSYC imaging of the Extended Chandra Deep Field-South. LAEs were selected to have observed frame equivalent widths >80 angstrom and emission line fluxes >1.5 x 10(-17) ergs cm(-2) s(-1). Only 1% of our LAE sample appears to host AGNs. The LAEs exhibit a moderate spatial correlation length of r(0) = 3.6(-1.0)(+0.8) Mpc, corresponding to a bias factor b = 1.7(-0.4)(+0.3), which implies median dark matter halo masses of log(10)M(med) = 10.9(-0.9)(+0.5) M-circle dot. Comparing the number density of LAEs, 1.5 +/- 0.3 x 10(-3) Mpc(-3), with the number density of these halos finds a mean halo occupation similar to 1%-10%. The evolution of galaxy bias with redshift implies that most z 3: 1 LAEs evolve into present-day galaxies with L < 2.5L*, whereas other z > 3 galaxy populations typically evolve into more massive galaxies. Halo merger trees show that z 0 descendants occupy halos with a wide range of masses, with a median descendant mass close to that of L*. Only 30% of LAEs have sufficient stellar mass (>similar to 3 x 10(9) M-circle dot) to yield detections in deep Spitzer IRAC imaging. A two-population SED fit to the stacked UBVRIzJK+[3.6, 4.5, 5.6, 8.0] mu m fluxes of the IRAC-undetected objects finds that the typical LAE has low stellar mass (1.0(-0.4)(+0.6) 10(9) M-circle dot), moderate star formation rate (2 +/- 1 M-circle dot yr(-1)), a young component age of 20(-10)(+30) Myr, and little dust (A(V) < 0: 2). The bestfit model has 20% of the mass in the young stellar component, but models without evolved stars are also allowed.
- ItemNew Spectroscopic Confirmations of Lyα Emitters at Z ∼ 7 from the LAGER Survey(2022) Harish, Santosh; Wold, Isak G. B.; Malhotra, Sangeeta; Rhoads, James E.; Hu, Weida; Wang, Junxian; Zheng, Zhen-ya; Barrientos, L. Felipe; Gonzalez-Lopez, Jorge; Perez, Lucia A.; Khostovan, Ali Ahmad; Infante, Leopoldo; Jiang, Chunyan; Moya-Sierralta, Cristobal; Pharo, John; Valdes, Francisco; Yang, HuanWe report spectroscopic confirmations of 15 Ly alpha galaxies at z similar to 7, implying a spectroscopic confirmation rate of similar to 80% on candidates selected from the Ly alpha Galaxies in the Epoch of Reionization (LAGER), which is the largest (24 deg(2)) survey aimed at finding Ly alpha emitters (LAEs) at z similar to 7 and uses deep narrowband imaging from the Dark Energy Camera at CTIO. LAEs at high redshifts are sensitive probes of cosmic reionization, and narrowband imaging is a robust and effective method for selecting a large number of LAEs. In this work, we present results from the spectroscopic follow-up of LAE candidates in two LAGER fields, COSMOS and WIDE-12, using observations from Keck/LRIS. We report the successful detection of Ly alpha emission in 15 candidates. Three of these in COSMOS have matching confirmations from a previous spectroscopic follow-up and are part of the overdense region, LAGER-z7OD1. Two other candidates that were not detected with LRIS have prior spectroscopic confirmations from Magellan. Including these, we obtain a spectroscopic confirmation success rate of similar to 80% for LAGER LAE candidates. Thorough checks were performed to reject the possibility of these detections being foreground emission resulting with a probability of, at most, one contaminant. We do not detect any other UV nebular lines in our LRIS spectra, apart from Ly alpha. We estimate a 2 sigma upper limit for the ratio of N v/Ly alpha, f (NV)/f (Ly alpha ) less than or similar to 0.27. Including confirmations from this work, a total of 33 LAE sources from LAGER are now spectroscopically confirmed. LAGER has more than doubled the sample of spectroscopically confirmed LAE sources at z similar to 7.
- ItemPortable adaptive optics for exoplanet imaging(2021) Zhu, Yong-Tian; Dou, Jiang-Pei; Zhang, Xi; Zhao, Gang; Guo, Jing; Infante, LeopoldoThe portable adaptive optics (PAO) device is a low-cost and compact system, designed for 4-meter class telescopes that have no adaptive optics (AO) system, because of the physical space limitation at the Nasmyth or Cassegrain focus and the historically high cost of conventional AO. The initial scientific observations of the PAO are focused on the direct imaging of exoplanets and sub-stellar companions. This paper discusses the concept of PAO and the associated high-contrast imaging performance in our recent observational runs. PAO deliver a Strehl ratio better than 60% in H band under median seeing conditions of 1 ''. Combined with our dedicated image rotation and subtraction (IRS) technique and the optimized IRS (O-IRS) algorithm, the averaged contrast ratio for a 5 <= V-mag <= 9 primary star is 1.3 x 10(-5) and 3.3 x 10(-6) at angular distance of 0.36 '' with exposure time of 7 minutes and 2 hours, respectively. PAO has successfully revealed the known exoplanet of kappa And b in our recent observation with the 3.5-meter ARC telescope at Apache Point Observatory. We have performed the associated astrometry and photometry analysis of the recovered kappa And b planet, which gives a projected separation of 0.984 '' +/- 0.05 '', a position angle of 51.1 degrees +/- 0.5 degrees and a mass of 10.15(-1.255)(+2.19) M-Jup. These results demonstrate that PAO can be used for direct imaging of exoplanets with medium-sized telescopes.
- ItemRevealing the Nature of a Lyα Halo in a Strongly Lensed Interacting System at z=2.92(2022) Solimano, Manuel; Gonzalez-Lopez, Jorge; Aravena, Manuel; Johnston, Evelyn J.; Moya-Sierralta, Cristobal; Barrientos, Luis F.; Baylis, Matthew B.; Gladders, Michael; Infante, Leopoldo; Ledoux, Cedric; Lopez, Sebastian; Poudel, Suraj; Rigby, Jane R.; Sharon, Keren; Tejos, NicolasSpatially extended halos of H i Ly alpha emission are now ubiquitously found around high-redshift star-forming galaxies. But our understanding of the nature and powering mechanisms of these halos is still hampered by the complex radiative transfer effects of the Ly alpha line and limited angular resolution. In this paper, we present resolved Multi Unit Spectroscopic Explorer (MUSE) observations of SGAS J122651.3+215220, a strongly lensed pair of L* galaxies at z = 2.92 embedded in a Ly alpha halo of L (Ly alpha ) = (6.2 +/- 1.3) x 10(42) erg s(-1). Globally, the system shows a line profile that is markedly asymmetric and redshifted, but its width and peak shift vary significantly across the halo. By fitting the spatially binned Ly alpha spectra with a collection of radiative transfer galactic wind models, we infer a mean outflow expansion velocity of approximate to 211 km s(-1), with higher values preferentially found on both sides of the system's major axis. The velocity of the outflow is validated with the blueshift of low-ionization metal absorption lines in the spectra of the central galaxies. We also identify a faint (M (1500) approximate to -16.7) companion detected in both Ly alpha and the continuum, whose properties are in agreement with a predicted population of satellite galaxies that contribute to the extended Ly alpha emission. Finally, we briefly discuss the impact of the interaction between the central galaxies on the properties of the halo and the possibility of in situ fluorescent Ly alpha production.
- ItemSubaru weak lensing measurement of a z=0.81 cluster discovered by the Atacama Cosmology Telescope Survey(2013) Miyatake, Hironao; Nishizawa, Atsushi J.; Takada, Masahiro; Mandelbaum, Rachel; Mineo, Sogo; Aihara, Hiroaki; Spergel, David N.; Bickerton, Steven J.; Bond, J. Richard; Gralla, Megan; Hajian, Amir; Hilton, Matt; Hincks, Adam D.; Hughes, John P.; Infante, Leopoldo; Lin, Yen-Ting; Lupton, Robert H.; Marriage, Tobias A.; Marsden, Danica; Menanteau, Felipe; Miyazaki, Satoshi; Moodley, Kavilan; Niemack, Michael D.; Oguri, Masamune; Price, Paul A.; Reese, Erik D.; Sifon, Cristobal; Wollack, Edward J.; Yasuda, NaokiWe present a Subaru weak lensing measurement of ACT-CL J0022.2-0036, one of the most luminous, high-redshift (z = 0.81) Sunyaev-Zel'dovich (SZ) clusters discovered in the 268 deg(2) equatorial region survey of the Atacama Cosmology Telescope that overlaps with Sloan Digital Sky Survey (SDSS) Stripe 82 field. Ours is the first weak lensing study with Subaru at such high redshifts. For the weak lensing analysis using i'-band images, we use a model-fitting (Gauss-Laguerre shapelet) method to measure shapes of galaxy images, where we fit galaxy images in different exposures simultaneously to obtain best-fitting ellipticities taking into account the different point spread functions (PSFs) in each exposure. We also take into account the astrometric distortion effect on galaxy images by performing the model fitting in the world coordinate system. To select background galaxies behind the cluster at z = 0.81, we use photometric redshift estimates for every galaxy derived from the co-added images of multi-passband Br'i'z'Y, with PSF matching/homogenization. After a photometric redshift cut for background galaxy selection, we detect the tangential weak lensing distortion signal with a total signal-to-noise ratio of about 3.7. By fitting a Navarro-Frenk-White model to the measured shear profile, we find the cluster mass to be M-200 (rho) over barm = [7.5(-2.8)(+3.2)(stat.)(+1.3)(-0.6)(sys.)] x 10(14) M-circle dot h(-1). The weak lensing-derived mass is consistent with previous mass estimates based on the SZ observation, with assumptions of hydrostatic equilibrium and virial theorem, as well as with scaling relations between SZ signal and mass derived from weak lensing, X-ray and velocity dispersion, within the measurement errors. We also show that the existence of ACT-CL J0022.2-0036 at z = 0.81 is consistent with the cluster abundance prediction of the Lambda-dominated cold dark matter structure formation model. We thus demonstrate the capability of Subaru-type ground-based images for studying weak lensing of high-redshift clusters.
- ItemTHE ACS FORNAX CLUSTER SURVEY. IV. DEPROJECTION OF THE SURFACE BRIGHTNESS PROFILES OF EARLY-TYPE GALAXIES IN THE VIRGO AND FORNAX CLUSTERS: INVESTIGATING THE "CORE/POWER-LAW DICHOTOMY"(2011) Glass, Lisa; Ferrarese, Laura; Cote, Patrick; Jordan, Andres; Peng, Eric; Blakeslee, John P.; Chen, Chin-Wei; Infante, Leopoldo; Mei, Simona; Tonry, John L.; West, Michael J.Although early observations with the Hubble Space Telescope (HST) pointed to a sharp dichotomy among early-type galaxies in terms of the logarithmic slope gamma' of their central surface brightness profiles, several studies in the past few years have called this finding into question. In particular, recent imaging surveys of 143 early-type galaxies belonging to the Virgo and Fornax Clusters using the Advanced Camera for Surveys (ACS) on board HST have not found a dichotomy in gamma', but instead a systematic progression from central luminosity deficit to excess relative to the inward extrapolation of the best-fitting global Sersic model. Given that earlier studies also found that the dichotomy persisted when analyzing the deprojected density profile slopes, we investigate the distribution of the three-dimensional luminosity density profiles of the ACS Virgo and Fornax Cluster Survey galaxies. Having fitted the surface brightness profiles with modified Sersic models, we then deproject the galaxies using an Abel integral and measure the inner slopes gamma(3D) of the resulting luminosity density profiles at various fractions of the effective radius R-e. We find no evidence of a dichotomy, but rather, a continuous variation in the central luminosity profiles as a function of galaxy magnitude. We introduce a parameter, Delta(3D), that measures the central deviation of the deprojected luminosity profiles from the global Sersic fit, showing that this parameter varies smoothly and systematically along the luminosity function.
- ItemThe ACS Fornax Cluster survey.: I.: Introduction to the survey and data reduction procedures(2007) Jordan, Andres; Blakeslee, John P.; Cote, Patrick; Ferrarese, Laura; Infante, Leopoldo; Mei, Simona; Merritt, David; Peng, Eric W.; Tonry, John L.; West, Michael J.The Fornax Cluster is a conspicuous cluster of galaxies in the southern hemisphere and the second largest collection of early-type galaxies within less than or similar to 20 Mpc after the Virgo Cluster. In this paper, we present a brief introduction to the ACS Fornax Cluster Survey - a program to image, in the F475W (g(475)) and F850LP (z(850)) bandpasses, 43 early-type galaxies in Fornax using the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. Combined with a companion survey of Virgo, the ACS Virgo Cluster Survey, this represents the most comprehensive imaging survey to date of early-type galaxies in cluster environments in terms of depth, spatial resolution, sample size, and homogeneity. We describe the selection of the program galaxies, their basic properties, and the main science objectives of the survey, which include the measurement of luminosities, colors, and structural parameters for globular clusters associated with these galaxies, an analysis of their isophotal properties and surface brightness profiles, and an accurate calibration of the surface brightness fluctuation distance indicator. Finally, we discuss the data reduction procedures adopted for the survey.
- ItemThe Atacama Cosmology Telescope: a measurement of the Cosmic Microwave Background power spectra at 98 and 150 GHz(2020) Choi, Steve K.; Hasselfield, Matthew; Ho, Shuay-Pwu Patty; Koopman, Brian; Lungu, Marius; Abitbol, Maximilian H.; Addison, Graeme E.; Ade, Peter A. R.; Aiola, Simone; Alonso, David; Amiri, Mandana; Amodeo, Stefania; Angile, Elio; Austermann, Jason E.; Baildon, Taylor; Battaglia, Nick; Beall, James A.; Bean, Rachel; Becker, Daniel T.; Bond, J. Richard; Bruno, Sarah Marie; Calabrese, Erminia; Calafut, Victoria; Campusano, Luis E.; Carrero, Felipe; Chesmore, Grace E.; Cho, Hsiao-mei; Clark, Susan E.; Cothard, Nicholas F.; Crichton, Devin; Crowley, Kevin T.; Darwish, Omar; Datta, Rahul; Denison, Edward, V; Devlin, Mark J.; Duell, Cody J.; Duff, Shannon M.; Duivenvoorden, Adriaan J.; Dunkley, Jo; Dunner, Rolando; Essinger-Hileman, Thomas; Fankhanel, Max; Ferraro, Simone; Fox, Anna E.; Fuzia, Brittany; Gallardo, Patricio A.; Gluscevic, Vera; Golec, Joseph E.; Grace, Emily; Gralla, Megan; Guan, Yilun; Hall, Kirsten; Halpern, Mark; Han, Dongwon; Hargrave, Peter; Henderson, Shawn; Hensley, Brandon; Hill, J. Colin; Hilton, Gene C.; Hilton, Matt; Hincks, Adam D.; Hlozek, Renee; Hubmayr, Johannes; Huffenberger, Kevin M.; Hughes, John P.; Infante, Leopoldo; Irwin, Kent; Jackson, Rebecca; Klein, Jeff; Knowles, Kenda; Kosowsky, Arthur; Lakey, Vincent; Li, Dale; Li, Yaqiong; Li, Zack; Lokken, Martine; Louis, Thibaut; MacInnis, Amanda; Madhavacheril, Mathew; Maldonado, Felipe; Mallaby-Kay, Maya; Marsden, Danica; Maurin, Loic; McMahon, Jeff; Menanteau, Felipe; Moodley, Kavilan; Morton, Tim; Naess, Sigurd; Namikawa, Toshiya; Nati, Federico; Newburgh, Laura; Nibarger, John P.; Nicola, Andrina; Niemack, Michael D.; Nolta, Michael R.; Orlowski-Sherer, John; Page, Lyman A.; Pappas, Christine G.; Partridge, Bruce; Phakathi, Phumlani; Prince, Heather; Puddu, Roberto; Qu, Frank J.; Rivera, Jesus; Robertson, Naomi; Rojas, Felipe; Salatino, Maria; Schaan, Emmanuel; Schillaci, Alessandro; Schmitt, Benjamin L.; Sehgal, Neelima; Sherwin, Blake D.; Sierra, Carlos; Sievers, Jon; Sifon, Cristobal; Sikhosana, Precious; Simon, Sara; Spergel, David N.; Staggs, Suzanne T.; Stevens, Jason; Storer, Emilie; Sunder, Dhaneshwar D.; Switzer, Eric R.; Thorne, Ben; Thornton, Robert; Trac, Hy; Treu, Jesse; Tucker, Carole; Vale, Leila R.; Van Engelen, Alexander; Van Lanen, Jeff; Vavagiakis, Eve M.; Wagoner, Kasey; Wang, Yuhan; Ward, Jonathan T.; Wollack, Edward J.; Xu, Zhilei; Zago, Fernando; Zhu, NingfengWe present the temperature and polarization angular power spectra of the CMB measured by the Atacama Cosmology Telescope (ACT) from 5400 deg(2) of the 2013-2016 survey, which covers >15000 deg(2) at 98 and 150 GHz. For this analysis we adopt a blinding strategy to help avoid confirmation bias and, related to this, show numerous checks for systematic error done before unblinding. Using the likelihood for the cosmological analysis we constrain secondary sources of anisotropy and foreground emission, and derive a "CMB-only" spectrum that extends to l = 4000. At large angular scales, foreground emission at 150 GHz is similar to 1% of TT and EE within our selected regions and consistent with that found by Planck. Using the same likelihood, we obtain the cosmological parameters for Lambda CDM for the ACT data alone with a prior on the optical depth of tau = 0.065 +/- 0.015. Lambda CDM is a good fit. The best-fit model has a reduced chi(2) of 1.07 (PTE = 0.07) with H-0 = 67.9 +/- 1.5 km/s/Mpc. We show that the lensing BB signal is consistent with Lambda CDM and limit the celestial EB polarization angle to psi(P) = 0.07 degrees +/- 0.09 degrees. We directly cross correlate ACT with Planck and observe generally good agreement but with some discrepancies in TE. All data on which this analysis is based will be publicly released.
- ItemTHE ATACAMA COSMOLOGY TELESCOPE: CALIBRATION WITH THE WILKINSON MICROWAVE ANISOTROPY PROBE USING CROSS-CORRELATIONS(2011) Hajian, Amir; Acquaviva, Viviana; Ade, Peter A. R.; Aguirre, Paula; Amiri, Mandana; Appel, John William; Felipe Barrientos, L.; Battistelli, Elia S.; Bond, John R.; Brown, Ben; Burger, Bryce; Chervenak, Jay; Das, Sudeep; Devlin, Mark J.; Dicker, Simon R.; Doriese, W. Bertrand; Dunkley, Joanna; Duenner, Rolando; Essinger-Hileman, Thomas; Fisher, Ryan P.; Fowler, Joseph W.; Halpern, Mark; Hasselfield, Matthew; Hernandez-Monteagudo, Carlos; Hilton, Gene C.; Hilton, Matt; Hincks, Adam D.; Hlozek, Renee; Huffenberger, Kevin M.; Hughes, David H.; Hughes, John P.; Infante, Leopoldo; Irwin, Kent D.; Baptiste Juin, Jean; Kaul, Madhuri; Klein, Jeff; Kosowsky, Arthur; Lau, Judy M.; Limon, Michele; Lin, Yen-Ting; Lupton, Robert H.; Marriage, Tobias A.; Marsden, Danica; Mauskopf, Phil; Menanteau, Felipe; Moodley, Kavilan; Moseley, Harvey; Netterfield, Calvin B.; Niemack, Michael D.; Nolta, Michael R.; Page, Lyman A.; Parker, Lucas; Partridge, Bruce; Reid, Beth; Sehgal, Neelima; Sherwin, Blake D.; Sievers, Jon; Spergel, David N.; Staggs, Suzanne T.; Swetz, Daniel S.; Switzer, Eric R.; Thornton, Robert; Trac, Hy; Tucker, Carole; Warne, Ryan; Wollack, Ed; Zhao, YueWe present a new calibration method based on cross-correlations with the Wilkinson Microwave Anisotropy Probe (WMAP) and apply it to data from the Atacama Cosmology Telescope (ACT). ACT's observing strategy and map-making procedure allows an unbiased reconstruction of the modes in the maps over a wide range of multipoles. By directly matching the ACT maps to WMAP observations in the multipole range of 400 < l < 1000, we determine the absolute calibration with an uncertainty of 2% in temperature. The precise measurement of the calibration error directly impacts the uncertainties in the cosmological parameters estimated from the ACT power spectra. We also present a combined map based on ACT and WMAP data that has a high signal-to-noise ratio over a wide range of multipoles.
- ItemThe Atacama Cosmology Telescope: DR4 maps and cosmological parameters(2020) Aiola, Simone; Calabrese, Erminia; Maurin, Loic; Naess, Sigurd; Schmitt, Benjamin L.; Abitbol, Maximilian H.; Addison, Graeme E.; Ade, Peter A. R.; Alonso, David; Amiri, Mandana; Amodeo, Stefania; Angile, Elio; Austermann, Jason E.; Baildon, Taylor; Battaglia, Nick; Beall, James A.; Bean, Rachel; Becker, Daniel T.; Bond, J. Richard; Bruno, Sarah Marie; Calafut, Victoria; Campusano, Luis E.; Carrero, Felipe; Chesmore, Grace E.; Cho, Hsiao-mei; Choi, Steve K.; Clark, Susan E.; Cothard, Nicholas F.; Crichton, Devin; Crowley, Kevin T.; Darwish, Omar; Datta, Rahul; Denison, Edward, V; Devlin, Mark J.; Duell, Cody J.; Duff, Shannon M.; Duivenvoorden, Adriaan J.; Dunkley, Jo; Dunner, Rolando; Essinger-Hileman, Thomas; Fankhanel, Max; Ferraro, Simone; Fox, Anna E.; Fuzia, Brittany; Gallardo, Patricio A.; Gluscevic, Vera; Golec, Joseph E.; Grace, Emily; Gralla, Megan; Guan, Yilun; Hall, Kirsten; Halpern, Mark; Han, Dongwon; Hargrave, Peter; Hasselfield, Matthew; Helton, Jakob M.; Henderson, Shawn; Hensley, Brandon; Hill, J. Colin; Hilton, Gene C.; Hilton, Matt; Hincks, Adam D.; Hlozek, Renee; Ho, Shuay-Pwu Patty; Hubmayr, Johannes; Huffenberger, Kevin M.; Hughes, John P.; Infante, Leopoldo; Irwin, Kent; Jackson, Rebecca; Klein, Jeff; Knowles, Kenda; Koopman, Brian; Kosowsky, Arthur; Lakey, Vincent; Li, Dale; Li, Yaqiong; Li, Zack; Lokken, Martine; Louis, Thibaut; Lungu, Marius; MacInnis, Amanda; Madhavacheril, Mathew; Maldonado, Felipe; Mallaby-Kay, Maya; Marsden, Danica; McMahon, Jeff; Menanteau, Felipe; Moodley, Kavilan; Morton, Tim; Namikawa, Toshiya; Nati, Federico; Newburgh, Laura; Nibarger, John P.; Nicola, Andrina; Niemack, Michael D.; Nolta, Michael R.; Orlowski-Sherer, John; Page, Lyman A.; Pappas, Christine G.; Partridge, Bruce; Phakathi, Phumlani; Pisano, Giampaolo; Prince, Heather; Puddu, Roberto; Qu, Frank J.; Rivera, Jesus; Robertson, Naomi; Rojas, Felipe; Salatino, Maria; Schaan, Emmanuel; Schillaci, Alessandro; Sehgal, Neelima; Sherwin, Blake D.; Sierra, Carlos; Sievers, Jon; Sifon, Cristobal; Sikhosana, Precious; Simon, Sara; Spergel, David N.; Staggs, Suzanne T.; Stevens, Jason; Storer, Emilie; Sunder, Dhaneshwar D.; Switzer, Eric R.; Thorne, Ben; Thornton, Robert; Hy Trac; Treu, Jesse; Tucker, Carole; Vale, Leila R.; Van Engelen, Alexander; Van Lanen, Jeff; Vavagiakis, Eve M.; Wagoner, Kasey; Wang, Yuhan; Ward, Jonathan T.; Wollack, Edward J.; Xu, Zhilei; Zago, Fernando; Zhu, NingfengWe present new arcminute-resolution maps of the Cosmic Microwave Background temperature and polarization anisotropy from the Atacama Cosmology Telescope, using data taken from 2013-2016 at 98 and 150 GHz. The maps cover more than 17,000 deg(2), the deepest 600 deg(2) with noise levels below 10 mu K-arcmin. We use the power spectrum derived from almost 6,000 deg(2) of these maps to constrain cosmology. The ACT data enable a measurement of the angular scale of features in both the divergence-like polarization and the temperature anisotropy, tracing both the velocity and density at last-scattering. From these one can derive the distance to the last-scattering surface and thus infer the local expansion rate, H-0. By combining ACT data with large-scale information from WMAP we measure H-0 = 67.6 +/- 1.1 km/s/Mpc, at 68% confidence, in excellent agreement with the independently-measured Planck satellite estimate (from ACT alone we find H-0 = 67.9 +/- 1.5 km/s/Mpc). The Lambda CDM model provides a good fit to the ACT data, and we find no evidence for deviations: both the spatial curvature, and the departure from the standard lensing signal in the spectrum, are zero to within 1 sigma; the number of relativistic species, the primordial Helium fraction, and the running of the spectral index are consistent with Lambda CDM predictions to within 1.5-2.2 sigma. We compare ACT, WMAP, and Planck at the parameter level and find good consistency; we investigate how the constraints on the correlated spectral index and baryon density parameters readjust when adding CMB large-scale information that ACT does not measure. The DR4 products presented here will be publicly released on the NASA Legacy Archive for Microwave Background Data Analysis.
- ItemThe Atacama Cosmology Telescope: Physical Properties and Purity of a Galaxy Cluster Sample Selected via the Sunyaev-Zel'dovich Effect(2010) Menanteau, Felipe; González, Jorge; Juin, Jean-Baptiste; Marriage, Tobias A.; Reese, Erik D.; Acquaviva, Viviana; Aguirre, Paula; Appel, John William; Baker, Andrew J.; Barrientos, L. Felipe; Battistelli, Elia S.; Bond, J. Richard; Das, Sudeep; Deshpande, Amruta J.; Devlin, Mark J.; Dicker, Simon; Dunkley, Joanna; Dünner, Rolando; Essinger-Hileman, Thomas; Fowler, Joseph W.; Hajian, Amir; Halpern, Mark; Hasselfield, Matthew; Hernández-Monteagudo, Carlos; Hilton, Matt; Hincks, Adam D.; Hlozek, Renée; Huffenberger, Kevin M.; Hughes, John P.; Infante, Leopoldo; Irwin, Kent D.; Klein, Jeff; Kosowsky, Arthur; Lin, Yen-Ting; Marsden, Danica; Moodley, Kavilan; Niemack, Michael D.; Nolta, Michael R.; Page, Lyman A.; Parker, Lucas; Partridge, Bruce; Sehgal, Neelima; Sievers, Jon; Spergel, David N.; Staggs, Suzanne T.; Swetz, Daniel; Switzer, Eric; Thornton, Robert; Trac, Hy; Warne, Ryan; Wollack, EdWe present optical and X-ray properties for the first confirmed galaxy cluster sample selected by the Sunyaev-Zel'dovich effect (SZE) from 148 GHz maps over 455 deg(2) of sky made with the Atacama Cosmology Telescope (ACT). These maps, coupled with multi-band imaging on 4 m class optical telescopes, have yielded a sample of 23 galaxy clusters with redshifts between 0.118 and 1.066. Of these 23 clusters, 10 are newly discovered. The selection of this sample is approximately mass limited and essentially independent of redshift. We provide optical positions, images, redshifts, and X-ray fluxes and luminosities for the full sample, and X-ray temperatures of an important subset. The mass limit of the full sample is around 8.0 x 10(14) M-circle dot, with a number distribution that peaks around a redshift of 0.4. For the 10 highest significance SZE-selected cluster candidates, all of which are optically confirmed, the mass threshold is 1 x 10(15) M-circle dot and the redshift range is 0.167-1.066. Archival observations from Chandra, XMM-Newton, and ROSAT provide X-ray luminosities and temperatures that are broadly consistent with this mass threshold. Our optical follow-up procedure also allowed us to assess the purity of the ACT cluster sample. Eighty (one hundred) percent of the 148 GHz candidates with signal-to-noise ratios greater than 5.1 (5.7) are confirmed as massive clusters. The reported sample represents one of the largest SZE-selected sample of massive clusters over all redshifts within a cosmologically significant survey volume, which will enable cosmological studies as well as future studies on the evolution, morphology, and stellar populations in the most massive clusters in the universe.
- ItemThe Atacama Cosmology Telescope: Sunyaev-Zel'dovich-Selected Galaxy Clusters at 148 GHz in the 2008 Survey(2011) Marriage, Tobias A.; Acquaviva, Viviana; Ade, Peter A. R.; Aguirre, Paula; Amiri, Mandana; Appel, John William; Barrientos, L. Felipe; Battistelli, Elia S.; Bond, J. Richard; Brown, Ben; Burger, Bryce; Chervenak, Jay; Das, Sudeep; Devlin, Mark J.; Dicker, Simon R.; Bertrand Doriese, W.; Dunkley, Joanna; Dünner, Rolando; Essinger-Hileman, Thomas; Fisher, Ryan P.; Fowler, Joseph W.; Hajian, Amir; Halpern, Mark; Hasselfield, Matthew; Hernández-Monteagudo, Carlos; Hilton, Gene C.; Hilton, Matt; Hincks, Adam D.; Hlozek, Renée; Huffenberger, Kevin M.; Handel Hughes, David; Hughes, John P.; Infante, Leopoldo; Irwin, Kent D.; Baptiste Juin, Jean; Kaul, Madhuri; Klein, Jeff; Kosowsky, Arthur; Lau, Judy M.; Limon, Michele; Lin, Yen-Ting; Lupton, Robert H.; Marsden, Danica; Martocci, Krista; Mauskopf, Phil; Menanteau, Felipe; Moodley, Kavilan; Moseley, Harvey; Netterfield, Calvin B.; Niemack, Michael D.; Nolta, Michael R.; Page, Lyman A.; Parker, Lucas; Partridge, Bruce; Quintana, Hernan; Reese, Erik D.; Reid, Beth; Sehgal, Neelima; Sherwin, Blake D.; Sievers, Jon; Spergel, David N.; Staggs, Suzanne T.; Swetz, Daniel S.; Switzer, Eric R.; Thornton, Robert; Trac, Hy; Tucker, Carole; Warne, Ryan; Wilson, Grant; Wollack, Ed; Zhao, YueWe report on 23 clusters detected blindly as Sunyaev-Zel'dovich (SZ) decrements in a 148 GHz, 455 deg(2) map of the southern sky made with data from the Atacama Cosmology Telescope 2008 observing season. All SZ detections announced in this work have confirmed optical counterparts. Ten of the clusters are new discoveries. One newly discovered cluster, ACT-CL J0102-4915, with a redshift of 0.75 ( photometric), has an SZ decrement comparable to the most massive systems at lower redshifts. Simulations of the cluster recovery method reproduce the sample purity measured by optical follow-up. In particular, for clusters detected with a signal-to-noise ratio greater than six, simulations are consistent with optical follow-up that demonstrated this subsample is 100% pure. The simulations further imply that the total sample is 80% complete for clusters with mass in excess of 6 x 10(14) solar masses referenced to the cluster volume characterized by 500 times the critical density. The Compton y-X-ray luminosity mass comparison for the 11 best-detected clusters visually agrees with both self-similar and non-adiabatic, simulation-derived scaling laws.
- ItemThe clustering of Lyα emitters in a ΛCDM Universe(2008) Orsi, Alvaro; Lacey, Cedric G.; Baugh, Carlton M.; Infante, LeopoldoWe combine a semi-analytical model of galaxy formation with a very large simulation which follows the growth of a large-scale structure in a Lambda cold dark matter (Lambda CDM) universe to predict the clustering of Ly alpha emitters. We find that the clustering strength of Ly alpha emitters has only a weak dependence on Ly alpha luminosity but a strong dependence on redshift. With increasing redshift, Ly alpha emitters trace progressively rarer, higher density regions of the universe. Due to the large volume of the simulation, over 100 times bigger than any previously used for this application, we can construct mock catalogues of Ly alpha emitters and study the sample variance of current and forthcoming surveys. We find that the number and clustering of Ly alpha emitters in our mock catalogues are in agreement with measurements from current surveys, but there is a considerable scatter in these quantities. We argue that a proposed survey of emitters at z = 8.8 should be extended significantly in solid angle to allow a robust measurement of Ly alpha emitter clustering.
- ItemThe host galaxies and environment of Chandra-selected active galactic nuclei in the deep ACS GTO cluster fields(2007) Martel, Andre R.; Menanteau, Felipe; Tozzi, Paolo; Ford, Holland C.; Infante, LeopoldoWe present catalogs and images of optical counterparts to the Chandra-selected X-ray sources found in the fields of the five clusters RX J0152-1357, RX J0849+4452, RDCS J0910+5422, MS 1054-0321, and RDCS J1252-2927, which were imaged with the Advanced Camera for Surveys as part of the ACS Guaranteed Time Observer programs. A total of 98 X-ray sources fall within the ACS mosaics, and positive identifications are made for similar to 96% of them, including confirmed cluster members. We classify the sources as active galactic nuclei (AGNs) or QSOs depending on their X-ray output. The log N(>S)-log S test indicates a significant overdensity of X-ray sources in the RX J0152-1357, RDCS J0910+5422, and MS 1054-0321 fields with respect to the CDF-S, suggesting an association of some X-ray sources with the large-scale structure of the clusters. From the asymmetry and concentration indices, similar to 52% of the optical counterparts are early-type galaxies, similar to 35%late- type, and the remainder irregular. A blue core is found in approximately half of the early-type galaxies. From visual examination, approximately 40% of the counterparts possess an unresolved nucleus, a common signature of nuclear activity. A majority of these nuclei are found in near face-on late-type galaxies although selection effects might be important. The X-ray to optical flux ratio of the nuclei correlates with the inclination angle of the late-type galaxies but not of the early types, as expected if dust is significant in the circumnuclear regions. The AGNs possess a similar to 50% excess of nearby companions compared to the overall galaxy population in the same fields. The surface density of the X-ray sources is highest at projected radii of less than or similar to 1 Mpc from the cluster center and relatively flat at larger radii. We describe the morphology and environment of the cluster members and compare them with the other optical counterparts.
- ItemThe Hubble Deep Hydrogen Alpha (HDHα) Project. I. Catalog of Emission-line Galaxies(2024) Zhu, Shuairu; Zheng, Zhen-Ya; Rhoads, James; Wang, Junxian; Jiang, Linhua; Jiang, Chunyan; Yuan, Fang-Ting; Rahna, P. T.; Hu, Weida; Lin, Ruqiu; Shan, Huanyuan; Xu, Chun; Infante, Leopoldo; Barrientos, L. Felipe; Zheng, Xianzhong; Fang, Guanwen; Liang, ZhixiongWe present the first results of the Hubble Deep Hydrogen Alpha (HDHα) project, which analyzes the space-borne deep Hα narrowband imaging data in the GOODS-S region. The HDHα data comprises 72 orbits' images taken with the Hubble Space Telescope (HST) Advanced Camera for Surveys/Wide Field Channel F658N filter. The exposure time varies across a total area of ∼76.1 arcmin2, adding up to a total exposure time of 195.7 ks, among which 68.8 ks are spent in the deepest region. These images are aligned, reprojected, and combined to have the same pixel grid as the Hubble Legacy Fields. The scientific goals of the HDHα include establishing a sample of emission-line galaxies (ELGs) including [O III] emitters at z ∼ 0.3, [O II] emitters at z ∼ 0.8, and Lyα emitters (LAEs) at z ∼ 4.4, studying the line morphology of ELGs with high resolution imaging data, and statistically analyzing the line luminosity functions and line equivalent-width distributions of ELGs selected with HST. Furthermore, the HDHα project enhances the legacy value of the GOODS-S field by contributing the first HST-based narrowband image to the existing data sets, which includes the HST broadband data and other ancillary data from X-ray to radio taken by other facilities. In this paper, we describe the data reduction process of the HDHα, select ELGs based on HST's F658N and broadband data, validate the redshifts of the selected candidates by crossmatching with the public spectroscopic catalogs in the GOODS-S, and present a final catalog of the confirmed [O III] emitters at z ∼ 0.3, [O II] emitters at z ∼ 0.8, and LAEs at z ∼ 4.4....
- ItemThe Multiwavelength Survey by Yale-Chile (MUSYC)(2008) Blanc, Guillermo A.; Lira, Paulina; Barrientos, L. Felipe; Aguirre, Paula; Francke, Harold; Taylor, Edward N.; Quadri, Ryan; Marchesini, Danilo; Infante, Leopoldo; Gawiser, Eric; Hall, Patrick B.; Willis, Jon P.; Herrera, David; Maza, JoseWe present K-band imaging of two similar to 30' x 30' fields covered by the Multiwavelength Survey by Yale-Chile (MUSYC) Wide NIR Survey. The SDSS 1030+05 and Cast 1255 fields were imaged with the Infrared Side Port Imager (ISPI) on the 4 m Blanco telescope at the Cerro Tololo Inter-American Observatory (CTIO) to a 5 sigma point-source limiting depth of K similar to 20 (Vega). Combining these data with the MUSYC optical UBVRIz imaging, we created multiband K-selected source catalogs for both fields. These catalogs, together with the MUSYC K-band catalog of the Extended Chandra Deep Field South (ECDF-S) field, were used to select K 20 BzK galaxies over an area of 0.71 deg(2). This is the largest area ever surveyed for BzK galaxies. We present number counts, redshift distributions, and stellar masses for our sample of 3261 BzK galaxies (2502 star-forming [sBzK] and 759 passively evolving [pBzK]), as well as reddening and star formation rate estimates for the star-forming BzK systems. We also present two-point angular correlation functions and spatial correlation lengths for both sBzK and pBzK galaxies and show that previous estimates of the correlation function of these galaxies were affected by cosmic variance due to the small areas surveyed. We have measured correlation lengths r(0) of 8.89 +/- 2.03 and 10.82 +/- 1.72 Mpc for sBzK and pBzK galaxies, respectively. This is the first reported measurement of the spatial correlation function of passive BzK galaxies. In the Lambda CDM scenario of galaxy formation, these correlation lengths at z similar to 2 translate into minimum masses of similar to 4 x 10(12) and similar to 9 x 10(12) M-circle dot for the dark matter halos hosting sBzK and pBzK galaxies, respectively. The clustering properties of the galaxies in our sample are consistent with their being the descendants of bright Lyman break galaxies at z similar to 3, and the progenitors of present-day > 1L* galaxies.