Browsing by Author "Ansarinejad, B."

Now showing 1 - 6 of 6
  • No Thumbnail Available
    Item
    The Atacama Cosmology Telescope: A Catalog of >4000 Sunyaev-Zel'dovich Galaxy Clusters
    (2021) Hilton, M.; Sifon, C.; Naess, S.; Madhavacheril, M.; Oguri, M.; Rozo, E.; Rykoff, E.; Abbott, T. M. C.; Adhikari, S.; Aguena, M.; Aiola, S.; Allam, S.; Amodeo, S.; Amon, A.; Annis, J.; Ansarinejad, B.; Aros-Bunster, C.; Austermann, J. E.; Avila, S.; Bacon, D.; Battaglia, N.; Beall, J. A.; Becker, D. T.; Bernstein, G. M.; Bertin, E.; Bhandarkar, T.; Bhargava, S.; Bond, J. R.; Brooks, D.; Burke, D. L.; Calabrese, E.; Carrasco Kind, M.; Carretero, J.; Choi, S. K.; Choi, A.; Conselice, C.; Costa, L. N. da; Costanzi, M.; Crichton, D.; Crowley, K. T.; Dunner, R.; Denison, E. V.; Devlin, M. J.; Dicker, S. R.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Duff, S. M.; Duivenvoorden, A. J.; Dunkley, J.; Everett, S.; Ferraro, S.; Ferrero, I.; Ferte, A.; Flaugher, B.; Frieman, J.; Gallardo, P. A.; Garcia-Bellido, J.; Gaztanaga, E.; Gerdes, D. W.; Giles, P.; Golec, J. E.; Gralla, M. B.; Grandis, S.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Han, D.; Hartley, W. G.; Hasselfield, M.; Hill, J. C.; Hilton, G. C.; Hincks, A. D.; Hinton, S. R.; Ho, S-P. P.; Honscheid, K.; Hoyle, B.; Hubmayr, J.; Huffenberger, K. M.; Hughes, J. P.; Jaelani, A. T.; Jain, B.; James, D. J.; Jeltema, T.; Kent, S.; Knowles, K.; Koopman, B. J.; Kuehn, K.; Lahav, O.; Lima, M.; Lin, Y-T.; Lokken, M.; Loubser, S. I.; MacCrann, N.; Maia, M. A. G.; Marriage, T. A.; Martin, J.; McMahon, J.; Melchior, P.; Menanteau, F.; Miquel, R.; Miyatake, H.; Moodley, K.; Morgan, R.; Mroczkowski, T.; Nati, F.; Newburgh, L. B.; Niemack, M. D.; Nishizawa, A. J.; Ogando, R. L. C.; Orlowski-Scherer, J.; Page, L. A.; Palmese, A.; Partridge, B.; Paz-Chinchon, F.; Phakathi, P.; Plazas, A. A.; Robertson, N. C.; Romer, A. K.; Rosell, A. Carnero; Salatino, M.; Sanchez, E.; Schaan, E.; Schillaci, A.; Sehgal, N.; Serrano, S.; Shin, T.; Simon, S. M.; Smith, M.; Soares-Santos, M.; Spergel, D. N.; Staggs, S. T.; Storer, E. R.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; To, C.; Trac, H.; Ullom, J. N.; Vale, L. R.; Lanen, J. Van; Vavagiakis, E. M.; Vicente, J. De; Wilkinson, R. D.; Wollack, E. J.; Xu, Z.; Zhang, Y.
    We present a catalog of 4195 optically confirmed Sunyaev-Zel'dovich (SZ) selected galaxy clusters detected with signal-to-noise ratio >4 in 13,211 deg(2) of sky surveyed by the Atacama Cosmology Telescope (ACT). Cluster candidates were selected by applying a multifrequency matched filter to 98 and 150 GHz maps constructed from ACT observations obtained from 2008 to 2018 and confirmed using deep, wide-area optical surveys. The clusters span the redshift range 0.04 < z < 1.91 (median z = 0.52). The catalog contains 222 z > 1 clusters, and a total of 868 systems are new discoveries. Assuming an SZ signal versus mass-scaling relation calibrated from X-ray observations, the sample has a 90% completeness mass limit of M-500c > 3.8 x 10(14) M, evaluated at z = 0.5, for clusters detected at signal-to-noise ratio >5 in maps filtered at an angular scale of 24. The survey has a large overlap with deep optical weak-lensing surveys that are being used to calibrate the SZ signal mass-scaling relation, such as the Dark Energy Survey (4566 deg(2)), the Hyper Suprime-Cam Subaru Strategic Program (469 deg(2)), and the Kilo Degree Survey (825 deg(2)). We highlight some noteworthy objects in the sample, including potentially projected systems, clusters with strong lensing features, clusters with active central galaxies or star formation, and systems of multiple clusters that may be physically associated. The cluster catalog will be a useful resource for future cosmological analyses and studying the evolution of the intracluster medium and galaxies in massive clusters over the past 10 Gyr.
  • No Thumbnail Available
    Item
    The nature of sub-millimetre galaxies II: an ALMA comparison of SMG dust heating mechanisms
    (2022) Ansarinejad, B.; Shanks, T.; Bielby, R. M.; Metcalfe, N.; Infante, L.; Murphy, D. N. A.; Rosario, D. J.; Stach, S. M.
    We compare the contribution of active galactic nuclei (AGNs) and star formation towards dust heating in sub-mm galaxies (SMGs). We have used ALMA at 0.1-arcsec resolution to image a complete flux-limited sample of seven sub-mm sources previously shown to have spectral energy distributions that were as well-fitted by obscured AGN as star-forming galaxy templates. Indeed, two sub-mm sources were known to be quasars from their absorbed X-ray emission. We find the sub-mm sizes of all SMGs to be small (approximate to 1-2 kpc) and generally similar to 3 times smaller than any host detected in the near-infrared (NIR). In all cases, the five SMGs are comparable in sub-mm size to the two known quasars and four z approximate to 6 quasars, also observed with ALMA. We detect no evidence of diffuse spiral arms in this complete sample. We then convert the far-infrared (FIR) luminosities to star formation rate (SFR) surface densities and find that the SMGs occupy the same range as the known quasars in our sample. We conclude that in terms of sub-mm size, extent relative to host and SFR density as well as luminosity and mid-IR (MIR) colour, there is little distinction between the SMGs and sub-mm bright quasars. Finally, we present preliminary evidence that SMGs with higher MIR luminosities and sub-mm loud quasars tend to have dust components that range to hotter temperatures than their less luminous SMG counterparts. In light of these results, we continue to suggest that luminous SMGs may host dust-absorbed quasars that may simultaneously dominate the FIR and hard X-ray backgrounds.
  • No Thumbnail Available
    Item
    The nature of sub-millimetre galaxies II: an ALMA comparison of SMG dust heating mechanisms
    (2022) Ansarinejad, B.; Shanks, T.; Bielby, R. M.; Metcalfe, N.; Infante, L.; Murphy, D. N. A.; Rosario, D. J.; Stach, S. M.
    We compare the contribution of active galactic nuclei (AGNs) and star formation towards dust heating in sub-mm galaxies (SMGs). We have used ALMA at 0.1-arcsec resolution to image a complete flux-limited sample of seven sub-mm sources previously shown to have spectral energy distributions that were as well-fitted by obscured AGN as star-forming galaxy templates. Indeed, two sub-mm sources were known to be quasars from their absorbed X-ray emission. We find the sub-mm sizes of all SMGs to be small (approximate to 1-2 kpc) and generally similar to 3 times smaller than any host detected in the near-infrared (NIR). In all cases, the five SMGs are comparable in sub-mm size to the two known quasars and four z approximate to 6 quasars, also observed with ALMA. We detect no evidence of diffuse spiral arms in this complete sample. We then convert the far-infrared (FIR) luminosities to star formation rate (SFR) surface densities and find that the SMGs occupy the same range as the known quasars in our sample. We conclude that in terms of sub-mm size, extent relative to host and SFR density as well as luminosity and mid-IR (MIR) colour, there is little distinction between the SMGs and sub-mm bright quasars. Finally, we present preliminary evidence that SMGs with higher MIR luminosities and sub-mm loud quasars tend to have dust components that range to hotter temperatures than their less luminous SMG counterparts. In light of these results, we continue to suggest that luminous SMGs may host dust-absorbed quasars that may simultaneously dominate the FIR and hard X-ray backgrounds.
  • No Thumbnail Available
    Item
    The VST ATLAS Quasar Survey - II. Halo mass profiles of galaxies, LRGs and galaxy clusters via quasar and CMB lensing
    (2024) Eltvedt, Alice M.; Shanks, T.; Metcalfe, N.; Ansarinejad, B.; Barrientos, L. F.; Murphy, D. N. A.; Alexander, D. M.
    We cross-correlate a low-contamination subset of the VST ATLAS g < 22.5 quasar catalogue with g < 21.5 galaxy clusters, r < 21 galaxies and r < 19.5 luminous red galaxies (LRGs) to probe their halo mass profiles via quasar magnification bias caused by weak lensing. In the case of galaxy clusters, we find that at small scales their mass profiles are well fitted by Navarro, Frenk, and White models with masses within the expected range. For the galaxies, we find consistency with previous Sloan Digital Sky Survey-based results for the galaxy-quasar cross-correlation and the galaxy auto-correlation functions. Disagreement as to whether the cross-correlation results are in tension with Lambda cold dark matter appears due to different assumptions as to whether galaxies trace mass. We conclude that halo occupation distribution (HOD) models fit the galaxy-quasar lensing results better than models where galaxies trace the mass. We further test the cluster and galaxy HOD models in the 2-halo range using the Planck cosmic microwave background (CMB) lensing map, finding that the cross-correlation with both the poorest clusters and the galaxies may be marginally overpredicted by the above HOD models. Finally, we measure the magnification bias of LRGs using both quasar and CMB lensing and find that the observed quasar lensing amplitude may be approximate to 2x too high and, on larger scales, the CMB lensing amplitude may be too low to be explained by a standard LRG HOD model.
  • No Thumbnail Available
    Item
    The VST ATLAS Quasar Survey - III. Halo mass function via quasar clustering and quasar-CMB lensing cross-clustering
    (2024) Eltvedt, Alice M.; Shanks, T.; Metcalfe, N.; Ansarinejad, B.; Barrientos, L. F.; Murphy, D. N. A.; Alexander, D. M.
    We exploit the VST ATLAS quasar (QSO) catalogue to perform three measurements of the quasar halo mass profile. First, we make a new estimate of the angular autocorrelation function of approximate to 230 000 ATLAS quasars with z(photo)less than or similar to 2.5 and 17
  • No Thumbnail Available
    Item
    The VST ATLAS quasar survey I: Catalogue of photometrically selected quasar candidates
    (2023) Eltvedt, Alice M.; Shanks, T.; Metcalfe, N.; Ansarinejad, B.; Barrientos, L. F.; Sharp, R.; Malik, U.; Murphy, D. N. A.; Irwin, M.; Wilson, M.; Alexander, D. M.; Kovacs, Andras; Garcia-Bellido, Juan; Ahlen, Steven; Brooks, David; de la Macorra, Axel; Font-Ribera, Andreu; Gontcho, Satya Gontcho a; Honscheid, Klaus; Meisner, Aaron; Miquel, Ramon; Nie, Jundan; Tarle, Gregory; Vargas-Magana, Mariana; Zhou, Zhimin
    We present the VST ATLAS Quasar Survey, consisting of similar to 1229 000 quasar (QSO) candidates with 16 < g < 22.5 over similar to 4700 deg(2). The catalogue is based on VST ATLAS+NEOWISE imaging surveys and aims to reach a QSO sky density of 130 deg-2 for z < 2.2 and similar to 30 deg(-2) for z > 2.2. To guide our selection, we use X-ray/UV/optical/MIR data in the extended William Herschel Deep Field (WHDF) where we find a g < 22.5 broad-line QSO density of 269 +/- 67 deg(-2), roughly consistent with the expected similar to 196 deg(-2). We find that similar to 25 per cent of our QSOs are morphologically classed as optically extended. Overall, we find that in these deep data, MIR, UV, and X-ray selections are similar to 70-90 per cent complete while X-ray suffers less contamination than MIR and UV. MIR is however more sensitive than X-ray or UV to z > 2.2 QSOs at g < 22.5 and the S-X (0.5 - 10 keV) > 1 x10(-14) ergs cm(-2) s(-1) limit of eROSITA. We adjust the selection criteria from our previous 2QDES pilot survey and prioritize VST ATLAS candidates that show both UV and MIR excess, also selecting candidates initially classified as extended. We test our selections using data from DESI (which will be released in DR1) and 2dF to estimate the efficiency and completeness, and we use ANNz2 to determine photometric redshifts. Applying over the similar to 4700 deg(2) ATLAS area gives us similar to 917 000 z < 2.2 QSO candidates of which 472 000 are likely to be z < 2.2 QSOs, implying a sky density of similar to 100 deg(-2), which our WHDF analysis suggests will rise to at least 130 deg(-2) when eROSITA X-ray candidates are included. At z > 2.2, we find similar to 310() 000 candidates, of which 169 000 are likely to be QSOs for a sky density of similar to 36 deg(-2).