Browsing by Author "Lehmer, Bret D."

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    Lyα 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, Ezequiel
    We 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.
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    The XMM-SERVS Survey: XMM-Newton Point-source Catalogs for the W-CDF-S and ELAIS-S1 Fields
    (2021) Ni, Qingling; Brandt, W. N.; Chen, Chien-Ting; Luo, Bin; Nyland, Kristina; Yang, Guang; Zou, Fan; Aird, James; Alexander, David M.; Bauer, Franz Erik; Lacy, Mark; Lehmer, Bret D.; Mallick, Labani; Salvato, Mara; Schneider, Donald P.; Tozzi, Paolo; Traulsen, Iris; Vaccari, Mattia; Vignali, Cristian; Vito, Fabio; Xue, Yongquan; Banerji, Manda; Chow, Kate; Comastri, Andrea; Del Moro, Agnese; Gilli, Roberto; Mullaney, James; Paolillo, Maurizio; Schwope, Axel; Shemmer, Ohad; Sun, Mouyuan; Timlin III, John D.; Trump, Jonathan R.
    We present the X-ray point-source catalogs in two of the XMM-Spitzer Extragalactic Representative Volume Survey (XMM-SERVS) fields, W-CDF-S (4.6 deg(2)) and ELAIS-S1 (3.2 deg(2)), aiming to fill the gap between deep pencil-beam X-ray surveys and shallow X-ray surveys over large areas. The W-CDF-S and ELAIS-S1 regions were targeted with 2.3 and 1.0 Ms of XMM-Newton observations, respectively; 1.8 and 0.9 Ms exposures remain after flare filtering. The survey in W-CDF-S has a flux limit of 1.0 x 10(-14) erg cm(-2) s(-1) over 90% of its area in the 0.5-10 keV band; 4053 sources are detected in total. The survey in ELAIS-S1 has a flux limit of 1.3 x 10(-14) erg cm(-2) s(-1) over 90% of its area in the 0.5-10 keV band; 2630 sources are detected in total. Reliable optical-to-IR multiwavelength counterpart candidates are identified for approximate to 89% of the sources in W-CDF-S and approximate to 87% of the sources in ELAIS-S1. A total of 3129 sources in W-CDF-S and 1957 sources in ELAIS-S1 are classified as active galactic nuclei (AGNs). We also provide photometric redshifts for X-ray sources; approximate to 84% of the 3319/2001 sources in W-CDF-S/ELAIS-S1 with optical-to-near-IR forced photometry available have either spectroscopic redshifts or high-quality photometric redshifts. The completion of the XMM-Newton observations in the W-CDF-S and ELAIS-S1 fields marks the end of the XMM-SERVS survey data gathering. The approximate to 12,000 pointlike X-ray sources detected in the whole approximate to 13 deg(2) XMM-SERVS survey will benefit future large-sample AGN studies.