Browsing by Author "Barrientos, L. F."

Now showing 1 - 7 of 7
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    Correlations between H α equivalent width and galaxy properties at z = 0.47: Physical or selection-driven?
    (2021) Khostovan, A. A.; Malhotra, S.; Rhoads, J. E.; Harish, S.; Jiang, C.; Wang, J.; Wold, I.; Zheng, Z. -Y.; Barrientos, L. F.; Coughlin, A.; Hu, W.; Infante, L.; Perez, L. A.; Pharo, J.; Valdes, F.; Walker, A. R.
    The H alpha equivalent width (EW) is an observational proxy for specific star formation rate (sSFR) and a tracer of episodic, bursty star-formation activity. Previous assessments show that the H alpha EW strongly anticorrelates with stellar mass as M-0.25 similar to the sSFR - stellar mass relation. However, such a correlation could be driven or even formed by selection effects. In this study, we investigate how H alpha EW distributions correlate with physical properties of galaxies and how selection biases could alter such correlations using a z = 0.47 narrow-band-selected sample of 1572 H alpha emitters from the Ly alpha Galaxies in the Epoch of Reionization (LAGER) survey as our observational case study. The sample covers a 3 deg(2) area of COSMOS with a survey comoving volume of 1.1 x 10(5) Mpc(3). We assume an intrinsic EW distribution to form mock samples of H alpha emitters and propagate the selection criteria to match observations, giving us control on how selection biases can affect the underlying results. We find that H alpha EW intrinsically correlates with stellar mass as W-0 proportional to M-0.16 +/- 0.03 and decreases by a factor of similar to 3 from 10(7) M-circle dot to 10(10) M-circle dot, while not correcting for selection effects steepens the correlation as M-025 +/- 0.04, We find low-mass H alpha emitters to be similar to 320 times more likely to have rest-frame EW > 200 angstrom compared to high-mass H alpha emitters. Combining the intrinsic W-0-stellar mass correlation with an observed stellar mass function correctly reproduces the observed H alpha luminosity function, while not correcting for selection effects underestimates the number of bright emitters. This suggests that the W-0-stellar mass correlation when corrected for selection effects is physically significant and reproduces three statistical distributions of galaxy populations (line luminosity function, stellar mass function, EW distribution). At lower stellar masses, we find there are more high-EW outliers compared to high stellar masses, even after we take into account selection effects. Our results suggest that high sSFR outliers indicative of bursty star formation activity are intrinsically more prevalent in low-mass H alpha emitters and not a byproduct of selection effects.
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    First Results from the Lyman Alpha Galaxies in the Epoch of Reionization (LAGER) Survey: Cosmological Reionization at z similar to 7
    (2017) Zheng, Z. Y.; Wang, J. X.; Rhoads, J.; Infante Lira, Leopoldo; Malhotra, S.; Hu, W. D.; Walker, A. R.; Jiang, L. H.; Jiang C. Y.; Hibon, P.; Gonzalez, A.; Kong, X. U.; Zheng, X. Z.; Galaz, Gaspar; Barrientos, L. F.; Zheng, Z. Y.; Wang, J. X.; Rhoads, J.; Infante Lira, Leopoldo; Malhotra, S.; Hu, W. D.; Walker, A. R.; Jiang, L. H.; Jiang C. Y.; Hibon, P.; Gonzalez, A.; Kong, X. U.; Zheng, X. Z.; Galaz, Gaspar; Barrientos, Luis Felipe; Zheng, Z. Y.; Wang, J. X.; Rhoads, J.; Infante Lira, Leopoldo; Malhotra, S.; Hu, W. D.; Walker, A. R.; Jiang, L. H.; Jiang C. Y.; Hibon, P.; Gonzalez, A.; Kong, X. U.; Zheng, X. Z.; Galaz, Gaspar; Barrientos, Luis Felipe
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    Galaxy Clusters in the Line of Sight to Background Quasars. I. Survey Design and Incidence of Mg II Absorbers at Cluster Redshifts
    (2008) Lopez, S.; Barrientos, L. F.; Lira, P.; Padilla, N.; Gilbank, D. G.; Gladders, M. D.; Maza, J.; Tejos, N.; Vidal, M.; Yee, H. K. C.
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    The Atacama Cosmology Telescope (ACT): Beam Profiles and First SZ Cluster Maps
    (2010) Hincks, A. D.; Acquaviva, V.; Ade, P. A. R.; Aguirre, P.; Amiri, M.; Appel, J. W.; Barrientos, L. F.; Battistelli, E. S.; Bond, J. R.; Brown, B.; Burger, B.; Chervenak, J.; Das, S.; Devlin, M. J.; Dicker, S. R.; Doriese, W. B.; Dunkley, J.; Dünner, R.; Essinger-Hileman, T.; Fisher, R. P.; Fowler, J. W.; Hajian, A.; Halpern, M.; Hasselfield, M.; Hernández-Monteagudo, C.; Hilton, G. C.; Hilton, M.; Hlozek, R.; Huffenberger, K. M.; Hughes, D. H.; Hughes, J. P.; Infante, L.; Irwin, K. D.; Jimenez, R.; Juin, J. B.; Kaul, M.; Klein, J.; Kosowsky, A.; Lau, J. M.; Limon, M.; Lin, Y. -T.; Lupton, R. H.; Marriage, T. A.; Marsden, D.; Martocci, K.; Mauskopf, P.; Menanteau, F.; Moodley, K.; Moseley, H.; Netterfield, C. B.; Niemack, M. D.; Nolta, M. R.; Page, L. A.; Parker, L.; Partridge, B.; Quintana, H.; Reid, B.; Sehgal, N.; Sievers, J.; Spergel, D. N.; Staggs, S. T.; Stryzak, O.; Swetz, D. S.; Switzer, E. R.; Thornton, R.; Trac, H.; Tucker, C.; Verde, L.; Warne, R.; Wilson, G.; Wollack, E.; Zhao, Y.
    The Atacama Cosmology Telescope (ACT) is currently observing the cosmic microwave background with arcminute resolution at 148 GHz, 218 GHz, and 277 GHz. In this paper, we present ACT's first results. Data have been analyzed using a maximum-likelihood map-making method which uses B-splines to model and remove the atmospheric signal. It has been used to make high-precision beam maps from which we determine the experiment's window functions. This beam information directly impacts all subsequent analyses of the data. We also used the method to map a sample of galaxy clusters via the Sunyaev-Zel'dovich (SZ) effect and show five clusters previously detected with X-ray or SZ observations. We provide integrated Compton-y measurements for each cluster. Of particular interest is our detection of the z = 0.44 component of A3128 and our current non-detection of the low-redshift part, providing strong evidence that the further cluster is more massive as suggested by X-ray measurements. This is a compelling example of the redshift-independent mass selection of the SZ effect.
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    The Atacama Cosmology Telescope: A Measurement of the 600 < ell < 8000 Cosmic Microwave Background Power Spectrum at 148 GHz
    (2010) Fowler, J. W.; Acquaviva, V.; Ade, P. A. R.; Aguirre, P.; Amiri, M.; Appel, J. W.; Barrientos, L. F.; Battistelli, E. S.; Bond, J. R.; Brown, B.; Burger, B.; Chervenak, J.; Das, S.; Devlin, M. J.; Dicker, S. R.; Doriese, W. B.; Dunkley, J.; Dünner, R.; Essinger-Hileman, T.; Fisher, R. P.; Hajian, A.; Halpern, M.; Hasselfield, M.; Hernández-Monteagudo, C.; Hilton, G. C.; Hilton, M.; Hincks, A. D.; Hlozek, R.; Huffenberger, K. M.; Hughes, D. H.; Hughes, J. P.; Infante, L.; Irwin, K. D.; Jimenez, R.; Juin, J. B.; Kaul, M.; Klein, J.; Kosowsky, A.; Lau, J. M.; Limon, M.; Lin, Y. -T.; Lupton, R. H.; Marriage, T. A.; Marsden, D.; Martocci, K.; Mauskopf, P.; Menanteau, F.; Moodley, K.; Moseley, H.; Netterfield, C. B.; Niemack, M. D.; Nolta, M. R.; Page, L. A.; Parker, L.; Partridge, B.; Quintana, H.; Reid, B.; Sehgal, N.; Sievers, J.; Spergel, D. N.; Staggs, S. T.; Swetz, D. S.; Switzer, E. R.; Thornton, R.; Trac, H.; Tucker, C.; Verde, L.; Warne, R.; Wilson, G.; Wollack, E.; Zhao, Y.
    We present a measurement of the angular power spectrum of the cosmic microwave background (CMB) radiation observed at 148 GHz. The measurement uses maps with 1'.4 angular resolution made with data from the Atacama Cosmology Telescope (ACT). The observations cover 228 deg(2) of the southern sky, in a 4 degrees.2 wide strip centered on declination 53 degrees south. The CMB at arcminute angular scales is particularly sensitive to the Silk damping scale, to the Sunyaev-Zel'dovich (SZ) effect from galaxy clusters, and to emission by radio sources and dusty galaxies. After masking the 108 brightest point sources in our maps, we estimate the power spectrum between 600 < l < 8000 using the adaptive multi-taper method to minimize spectral leakage and maximize use of the full data set. Our absolute calibration is based on observations of Uranus. To verify the calibration and test the fidelity of our map at large angular scales, we cross-correlate the ACT map to the WMAP map and recover the WMAP power spectrum from 250 < l < 1150. The power beyond the Silk damping tail of the CMB (l similar to 5000) is consistent with models of the emission from point sources. We quantify the contribution of SZ clusters to the power spectrum by fitting to a model normalized to sigma(8) = 0.8. We constrain the model's amplitude A(SZ) < 1.63 (95% CL). If interpreted as a measurement of sigma(8), this implies sigma(SZ)(8) < 0.86 (95% CL) given our SZ model. A fit of ACT and WMAP five-year data jointly to a six-parameter Lambda CDM model plus point sources and the SZ effect is consistent with these results.
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    The Color Bimodality in Galaxy Clusters since z ~ 0.9
    (2008) Loh, Yeong-Shang; Ellingson, E.; Yee, H. K. C.; Gilbank, D. G.; Gladders, M. D.; Barrientos, L. F.
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    The Hubble Space Telescope Cluster Supernova Survey. III. Correlated Properties of Type Ia Supernovae and Their Hosts at 0.9 < Z < 1.46
    (2012) Meyers, J.; Aldering, G.; Barbary, K.; Barrientos, L. F.; Brodwin, M.; Dawson, K. S.; Deustua, S.; Doi, M.; Eisenhardt, P.; Faccioli, L.; Fakhouri, H. K.; Fruchter, A. S.; Gilbank, D. G.; Gladders, M. D.; Goldhaber, G.; Gonzalez, A. H.; Hattori, T.; Hsiao, E.; Ihara, Y.; Kashikawa, N.; Koester, B.; Konishi, K.; Lidman, C.; Lubin, L.; Morokuma, T.; Oda, T.; Perlmutter, S.; Postman, M.; Ripoche, P.; Rosati, P.; Rubin, D.; Rykoff, E.; Spadafora, A.; Stanford, S. A.; Suzuki, N.; Takanashi, N.; Tokita, K.; Yasuda, N.; Supernova Cosmology Project, The
    Using the sample of Type Ia supernovae (SNe Ia) discovered by the Hubble Space Telescope (HST) Cluster Supernova Survey and augmented with HST-observed SNe Ia in the Great Observatories Origins Deep Survey (GOODS) fields, we search for correlations between the properties of SNe and their host galaxies at high redshift. We use galaxy color and quantitative morphology to determine the red sequence in 25 clusters and develop a model to distinguish passively evolving early-type galaxies from star-forming galaxies in both clusters and the field. With this approach, we identify 6 SN Ia hosts that are early-type cluster members and 11 SN Ia hosts that are early-type field galaxies. We confirm for the first time at z > 0.9 that SNe Ia hosted by early-type galaxies brighten and fade more quickly than SNe Ia hosted by late-type galaxies. We also show that the two samples of hosts produce SNe Ia with similar color distributions. The relatively simple spectral energy distributions expected for passive galaxies enable us to measure stellar masses of early-type SN hosts. In combination with stellar mass estimates of late-type GOODS SN hosts from Thomson & Chary, we investigate the correlation of host mass with Hubble residual observed at lower redshifts. Although the sample is small and the uncertainties are large, a hint of this relation is found atz > 0.9. By simultaneously fitting the average cluster galaxy formation history and dust content to the red-sequence scatters, we show that the reddening of early-type cluster SN hosts is likely E(B - V) less than or similar to 0.06. The similarity of the field and cluster early-type host samples suggests that field early-type galaxies that lie on the red sequence may also be minimally affected by dust. Hence, the early-type-hosted SNe Ia studied here occupy a more favorable environment to use as well-characterized high-redshift standard candles than other SNe Ia.