Search Publications
The Fifth Data Release Sloan Digital Sky Survey/XMM-Newton Quasar Survey
Elvis, M.; Risaliti, G.; Young, M.
We present a catalog of 792 Fifth Data Release Sloan Digital Sky Survey quasars with optical spectra that have been observed serendipitously in the X-rays with the XMM-Newton. These quasars cover a redshift range of z = 0.11-5.41 and a magnitude range of i = 15.3-20.7. Substantial numbers of radio-loud (70) and broad absorption line (51) quasars e…
Biases and Uncertainties in Physical Parameter Estimates of Lyman Break Galaxies from Broadband Photometry
Ferguson, Henry C.; Giavalisco, Mauro; Somerville, Rachel S. +3 more
We investigate the biases and uncertainties in estimates of physical parameters of high-redshift Lyman break galaxies (LBGs), such as stellar mass, mean stellar population age, and star formation rate (SFR), obtained from broadband photometry. These biases arise from the simplifying assumptions often used in fitting the spectral energy distributio…
Magellan Spectroscopy of Low-Redshift Active Galactic Nuclei
Ho, Luis C.; Kim, Minjin
We present an atlas of moderate-resolution (R ≈ 1200-1600) optical spectra of 94 low-redshift (z lsim 0.5) active galactic nuclei taken with the Magellan 6.5 m Clay Telescope. The spectra mostly cover the rest-frame region ~3600-6000 Å. All the objects have pre-existing Hubble Space Telescope imaging, and they were chosen as part of an ongoing pro…
A Multi-color Optical Survey of the Orion Nebula Cluster. I. The Catalog
Panagia, N.; Robberto, M.; Da Rio, N. +4 more
We present U, B, V, I broadband, 6200 Å TiO mediumband, and Hα narrowband photometry of the Orion Nebula Cluster (ONC) obtained with the WFI imager at the ESO/MPI 2.2 telescope at La Silla Observatory. The nearly simultaneous observations cover the entire ONC in a field of about 34 × 34 arcmin. They enable us to determine stellar colors avoiding t…
X-Ray-Emitting Stars Identified from the ROSAT All-Sky Survey and the Sloan Digital Sky Survey
Anderson, Scott F.; Hawley, Suzanne L.; Szkody, Paula +7 more
The ROSAT All-Sky Survey (RASS) was the first imaging X-ray survey of the entire sky. Combining the RASS Bright and Faint Source Catalogs yields an average of about three X-ray sources per square degree. However, while X-ray source counterparts are known to range from distant quasars to nearby M dwarfs, the RASS data alone are often insufficient t…
Multiwavelength Photometry in the Globular Cluster M2
Dalessandro, E.; Beccari, G.; Ferraro, F. R. +3 more
We present a multiwavelength photometric analysis of the globular cluster M2. The data set has been obtained by combining high-resolution (Hubble Space Telescope/WFPC2 and ACS) and wide-field (Galaxy Evolution Explorer) space observations and ground-based (MEGACAM-CFHT, EMMI-NTT) images. The photometric sample covers the entire cluster extension f…
Deep Chandra Monitoring Observations of NGC 4278: Catalog of Source Properties
Zezas, A.; Gallagher, J.; King, A. R. +11 more
We present the properties of the discrete X-ray sources detected in our monitoring program of the globular cluster (GC) rich elliptical galaxy, NGC 4278, observed with Chandra ACIS-S in six separate pointings, resulting in a co-added exposure of 458 ks. From this deep observation, 236 sources have been detected within the region overlapped by all …
HST/ACS Emission Line Imaging of Low-redshift 3CR Radio Galaxies. I. The Data
Baum, Stefi A.; O'Dea, Christopher P.; Axon, David J. +11 more
We present 19 nearby (z < 0.3) 3CR radio galaxies imaged at low and high excitation as part of a Cycle 15 Hubble Space Telescope (HST) snapshot survey with the Advanced Camera for Surveys (ACS). These images consist of exposures of the Hα (6563 Å, plus [N II] contamination) and [O III]λ5007 emission lines using narrowband linear ramp filters ad…
Deep Optical Photometry of Six Fields in the Andromeda Galaxy
Ferguson, Henry C.; Brown, Thomas M.; Rich, R. Michael +7 more
Using the Advanced Camera for Surveys on the Hubble Space Telescope, we have obtained deep optical images reaching well below the oldest main-sequence turnoff in six fields of the Andromeda Galaxy. The fields fall at four positions on the southeast minor axis, one position in the giant stellar stream, and one position on the northeast major axis. …
Ten More New Sightlines for the Study of Intergalactic Helium, and Hundreds of Far-Ultraviolet-Bright Quasars, from the Sloan Digital Sky Survey, Galaxy Evolution Explorer, and Hubble Space Telescope
Anderson, Scott F.; Schneider, Donald P.; York, Donald G. +4 more
Absorption along quasar sightlines remains among the most sensitive direct measures of He II reionization in much of the intergalactic medium (IGM). Until recently, fewer than a half-dozen unobscured quasar sightlines suitable for the He II Gunn-Peterson test were known; although these handful demonstrated great promise, the small sample size limi…