Browsing by Author "Gronwall, Caryl"
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- ItemEVOLUTION IN THE CONTINUUM MORPHOLOGICAL PROPERTIES OF Lyα-EMITTING GALAXIES FROM z=3.1 TO z=2.1(2012) Bond, Nicholas A.; Gawiser, Eric; Guaita, Lucia; Padilla, Nelson; Gronwall, Caryl; Ciardullo, Robin; Lai, KamsonWe present a rest-frame ultraviolet morphological analysis of 108 z similar or equal to 2.1 Ly alpha emitters (LAEs) in the Extended Chandra Deep Field South and compare it to a similar sample of 171 LAEs at z similar or equal to 3.1. Using Hubble Space Telescope images from the Galaxy Evolution from Morphology and SEDs survey, Great Observatories Origins Deep Survey, and Hubble Ultradeep Field, we measure size and photometric component distributions, where photometric components are defined as distinct clumps of UV-continuum emission. At both redshifts, >80% of LAEs have observed half-light radii < 2 kpc, but the median half-light radius rises from 0.95 +/- 0.04 kpc at z = 3.1 to 1.41 +/- 0.14 kpc at z = 2.1. A similar evolution is seen in the sizes of individual rest-UV components, but there is no evidence for evolution in the number of multi-component systems. In the z = 2.1 sample, we see clear correlations between the size of an LAE and other physical properties derived from its spectral energy distribution (SED). LAEs are found to be larger for galaxies with higher stellar mass, star formation rate, and dust obscuration, but there is no evidence for a trend between equivalent width and half-light radius at either redshift. The presence of these correlations suggests that a wide range of objects are being selected by LAE surveys at z similar or equal to 2, including a significant fraction of objects for which a massive and moderately extended population of old stars underlies the young starburst giving rise to the Ly alpha emission.
- 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 = 2.1 : Stellar Masses, Dust, and Star Formation Histories from Spectral Energy Distribution Fitting.(2011) Guaita, Lucía; Padilla, Nelson; Treister, Ezequiel; Acquaviva, Viviana; Gawiser, Eric; Bond, Nicholas A.; Ciardullo, Robin; Kurczynski, Peter; Gronwall, Caryl; Lira, Paulina; Schawinski, Kevin
- 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.
- ItemSTACKED REST-FRAME ULTRAVIOLET SPECTRA OF Lyα-EMITTING AND CONTINUUM-SELECTED GALAXIES AT 2 < z < 3.5(2012) Berry, Michael; Gawiser, Eric; Guaita, Lucia; Padilla, Nelson; Treister, Ezequiel; Blanc, Guillermo A.; Ciardullo, Robin; Francke, Harold; Gronwall, CarylWe present properties of individual and composite rest-UV spectra of continuum-and narrowband-selected star-forming galaxies (SFGs) at a redshift of 2 < z < 3.5 discovered by the MUSYC collaboration in the Extended Chandra Deep Field-South. Among our sample of 81 UV-bright SFGs, 59 have R < 25.5, of which 32 have rest-frame equivalent widths of W-Ly alpha > 20 angstrom, the canonical limit to be classified as an Ly alpha-emitting galaxy. We divide our data set into subsamples based on properties that we are able to measure for each individual galaxy: Ly alpha equivalent width, rest-frame UV colors, and redshift. Among our subsample of galaxies with R < 25.5, those with rest frame W-Ly alpha > 20 angstrom have bluer UV continua, weaker low-ionization interstellar absorption lines, weaker C IV absorption, and stronger Si II* nebular emission than those with W-Ly alpha < 20 angstrom. We measure a velocity offset of Delta nu similar to 600 km s(-1) between Ly alpha emission and low-ionization absorption, which does not vary substantially among any of our subsamples. We find that the interstellar component, as opposed to the stellar component, dominates the high-ionization absorption line profiles. We find that the low-and high-ionization Si ionization states have similar kinematic properties, yet the low-ionization absorption is correlated with Ly alpha emission and the high-ionization absorption is not. These trends are consistent with outflowing neutral gas being in the form of neutral clouds embedded in ionized gas as previously suggested by Steidel et al. Moreover, our galaxies with bluer UV colors have stronger Ly alpha emission, weaker low-ionization absorption, and more prominent nebular emission line profiles. From a redshift of 2.7 < z < 3.5 to 2.0 < z < 2.7, our subsample of galaxies with W-Ly alpha < 20 angstrom shows no significant evolution in their physical properties or the nature of their outflows. Among our data set, UV-bright galaxies with W-Ly alpha > 20 angstrom exhibit weaker Ly alpha emission at lower redshifts, although we caution that this could be caused by spectroscopic confirmation of low Ly alpha equivalent width galaxies being harder at z similar to 3 than z similar to 2.
- ItemThe Evolution of Lyα-emitting Galaxies between z = 2.1 and z = 3.1(2012) Ciardullo, R.; Guaita, Lucía; Padilla, Nelson; Francke Henríquez, Harold Johanns Phillippe; Treister, Ezequiel; Gronwall, Caryl; Wolf, Christopher; McCathran, Emily; Bond, N.; Gawiser, Eric.; Feldmeier, John J.; Ciardullo, R.; Guaita, Lucía; Padilla, Nelson; Francke Henríquez, Harold Johanns Phillippe; Treister, Ezequiel; Gronwall, Caryl; Wolf, Christopher; McCathran, Emily; Bond, N.; Gawiser, Eric.; Feldmeier, John J.
- ItemThe One-hundred-deg2 DECam Imaging in Narrowbands (ODIN): Survey Design and Science Goals(2024) Lee, Kyoung-Soo; Gawiser, Eric; Park, Changbom; Yang, Yujin; Valdes, Francisco; Lang, Dustin; Ramakrishnan, Vandana; Moon, Byeongha; Firestone, Nicole; Appleby, Stephen; Artale, Maria Celeste; Andrews, Moira; Bauer, Franz; Benda, Barbara; Broussard, Adam; Chiang, Yi-Kuan; Ciardullo, Robin; Dey, Arjun; Farooq, Rameen; Gronwall, Caryl; Guaita, Lucia; Huang, Yun; Hwang, Ho Seong; Im, Sang Hyeok; Jeong, Woong-Seob; Karthikeyan, Shreya; Kim, Hwihyun; Kim, Seongjae; Kumar, Ankit; Nagaraj, Gautam R.; Nantais, Julie; Padilla, Nelson; Park, Jaehong; Pope, Alexandra; Popescu, Roxana; Schlegel, David; Seo, Eunsuk; Singh, Akriti; Song, Hyunmi; Troncoso, Paulina; Vivas, A. Katherina; Zabludoff, Ann; Zenteno, AlfredoWe describe the survey design and science goals for One-hundred-deg(2) DECam Imaging in Narrowbands (ODIN), a NOIRLab survey using the Dark Energy Camera (DECam) to obtain deep (AB similar to 25.7) narrowband images over an unprecedented area of sky. The three custom-built narrowband filters, N419, N501, and N673, have central wavelengths of 419, 501, and 673 nm and respective FWHM of 7.5, 7.6, and 10.0 nm, corresponding to Ly alpha at z = 2.4, 3.1, and 4.5 and cosmic times of 2.8, 2.1, and 1.4 Gyr, respectively. When combined with even deeper, public broadband data from the Hyper Suprime-Cam, DECam, and in the future, the Legacy Survey of Space and Time, the ODIN narrowband images will enable the selection of over 100,000 Ly alpha-emitting (LAE) galaxies at these epochs. ODIN-selected LAEs will identify protoclusters as galaxy overdensities, and the deep narrowband images enable detection of highly extended Ly alpha blobs (LABs). Primary science goals include measuring the clustering strength and dark matter halo connection of LAEs, LABs, and protoclusters, and their respective relationship to filaments in the cosmic web. The three epochs allow for the redshift evolution of these properties to be determined during the period known as Cosmic Noon, where star formation was at its peak. The narrowband filter wavelengths are designed to enable interloper rejection and further scientific studies by revealing [O II] and [O III] at z = 0.34, Ly alpha and He II 1640 at z = 3.1, and Lyman continuum plus Ly alpha at z = 4.5. Ancillary science includes similar studies of the lower-redshift emission-line galaxy samples and investigations of nearby star-forming galaxies resolved into numerous [O III] and [S II] emitting regions.
- ItemThe Physical Nature of Lyα-emitting Galaxies at z = 3.1(2006) Gawiser, Eric.; Blanc, Guillermo; Francke Henríquez, Harold Johanns Phillippe; Infante Lira, Leopoldo; Lira, Paulina; Treister, Ezequiel; van Dokkum, Pieter G.; Gronwall, Caryl; Ciardullo, R.; Castander, Francisco J.; Feldmeier, John J.; Franx, Marijn
- ItemTO STACK OR NOT TO STACK : SPECTRAL ENERGY DISTRIBUTION PROPERTIES OF Lyα-EMITTING GALAXIES AT z=2.1(2014) Vargas, Carlos J.; Bish, Hannah; Acquaviva, Viviana; Gawiser, Eric; Finkelstein, Steven L.; Ciardullo, Robin; Ashby, Matthew L. N.; Feldmeier, John; Ferguson, Henry; Padilla, Nelson; Gronwall, Caryl; Guaita, Lucía; Hagen, Alex; Koekemoer, Anton; Kurczynski, Peter; Newman, Jeffrey A.
- ItemTO STACK OR NOT TO STACK: SPECTRAL ENERGY DISTRIBUTION PROPERTIES OF Lyα-EMITTING GALAXIES AT z=2.1(2014) Vargas, Carlos J.; Bish, Hannah; Acquaviva, Viviana; Gawiser, Eric; Finkelstein, Steven L.; Ciardullo, Robin; Ashby, Matthew L. N.; Feldmeier, John; Ferguson, Henry; Gronwall, Caryl; Guaita, Lucia; Hagen, Alex; Koekemoer, Anton; Kurczynski, Peter; Newman, Jeffrey A.; Padilla, NelsonWe use the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS) GOODS-S multi-wavelength catalog to identify counterparts for 20 Ly alpha emitting (LAE) galaxies at z = 2.1. We build several types of stacked spectral energy distributions (SEDs) of these objects. We combine photometry to form average and median flux-stacked SEDs, and postage-stamp images to form average and median image-stacked SEDs. We also introduce scaled flux stacks that eliminate the influence of variation in overall brightness. We use the SED fitting code SpeedyMC to constrain the physical properties of individual objects and stacks. Our LAEs at z = 2.1 have stellar masses ranging from 2 x 10(7) M-circle dot to 8 x 10(9) M-circle dot (median = 3 x 10(8) M-circle dot), ages ranging from 4 Myr to 500 Myr (median = 100 Myr), and E(B - V) between 0.02 and 0.24 (median = 0.12). Although still low, this represents significantly more dust reddening than has been reported for LAEs at higher redshifts. We do not observe strong correlations between Ly alpha equivalent width (EW) and age or E(B - V). The Ly alpha radiative transfer (q) factors of our sample are predominantly close to one and do not correlate strongly with EW or E(B - V). The absence of strong correlations with EW or q implies that Ly alpha radiative transfer is highly anisotropic and/or prevents Ly alpha photons from scattering in dusty regions. The SED parameters of the flux stacks match the average and median values of the individual objects, with the flux-scaled median SED performing best with uncertainties reduced by a factor of two. Median image-stacked SEDs provide a poor representation of the median individual object, and none of the stacking methods capture the large dispersion of LAE properties.