Search Publications
A Remarkable Long-term Light Curve and Deep, Low-state Spectroscopy: Swift and XMM-Newton Monitoring of the NLS1 Galaxy Mkn 335
Fabian, Andrew C.; Komossa, S.; Gallo, Luigi C. +5 more
The narrow-line Seyfert 1 galaxy (NLS1) Mkn 335 is remarkable because it has repeatedly shown deep, long X-ray low states that show pronounced spectral structure. It has become one of the prototype active galactic nuclei (AGNs) in deep minimum X-ray states. Here we report on the continuation of our ongoing monitoring campaign with Swift and the ex…
The Advanced Camera for Surveys General Catalog: Structural Parameters for Approximately Half a Million Galaxies
Koekemoer, Anton M.; Conselice, Christopher J.; Weiner, Benjamin +18 more
We present the Advanced Camera for Surveys General Catalog (ACS-GC), a photometric and morphological database using publicly available data obtained with the Advanced Camera for Surveys (ACS) instrument on the Hubble Space Telescope. The goal of the ACS-GC database is to provide a large statistical sample of galaxies with reliable structural and d…
An XMM-Newton Survey of the Soft X-Ray Background. II. An All-Sky Catalog of Diffuse O VII and O VIII Emission Intensities
Henley, David B.; Shelton, Robin L.
We present an all-sky catalog of diffuse O VII and O VIII line intensities, extracted from archival XMM-Newton observations. This catalog supersedes our previous catalog, which covered the sky between l = 120° and l = 240°. We attempted to reduce the contamination from near-Earth solar wind charge exchange (SWCX) emission by excluding times of hig…
Photometry and Photometric Redshift Catalogs for the Lockman Hole Deep Field
Lutz, D.; Burwitz, V.; Salvato, M. +9 more
We present broadband photometry and photometric redshifts for 187,611 sources located in ~0.5 deg2 in the Lockman Hole area. The catalog includes 388 X-ray-detected sources identified with the very deep XMM-Newton observations available for an area of 0.2 deg2. The source detection was performed on the R c-, z'-, a…
The Sub-mJy Radio Population of the E-CDFS: Optical and Infrared Counterpart Identification
Brandt, W. N.; Tozzi, P.; Balestra, I. +9 more
We study a sample of 883 sources detected in a deep Very Large Array survey at 1.4 GHz in the Extended Chandra Deep Field South. This paper focuses on the identification of their optical and infrared (IR) counterparts. We use a likelihood-ratio technique that is particularly useful when dealing with deep optical images to minimize the number of sp…
Mid-infrared Spectral Variability Atlas of Young Stellar Objects
Ábrahám, P.; Kóspál, Á.; Henning, Th. +6 more
Optical and near-infrared variability is a well-known property of young stellar objects. However, a growing number of recent studies claim that a considerable fraction of them also exhibit mid-infrared flux changes. With the aim of studying and interpreting variability on a decadal timescale, here we present a mid-infrared spectral atlas containin…
Molecular Environments of 51 Planck Cold Clumps in the Orion Complex
Liu, Tie; Wu, Yuefang; Zhang, Huawei
A mapping survey of 51 Planck cold clumps projected on the Orion complex was performed with J = 1-0 lines of 12CO and 13CO with the 13.7 m telescope at the Purple Mountain Observatory. The mean column densities of the Planck gas clumps range from 0.5 to 9.5 × 1021 cm-2, with an average value of (2.9 ± 1.…
Spitzer Search for Dust Disks around Central Stars of Planetary Nebulae
De Marco, Orsola; Chu, You-Hua; Bilíková, Jana +2 more
Two types of dust disks have been discovered around white dwarfs (WDs): small dust disks within the Roche limits of their WDs and large dust disks around hot WDs extending to radial distances of 10-102 AU. The majority of the latter WDs are central stars of planetary nebulae (CSPNs). We have therefore used archival Spitzer Infrared Arra…
OPACOS: OVRO Post-AGB CO (1-0) Emission Survey. I. Data and Derived Nebular Parameters
Sahai, R.; Sánchez Contreras, C.
We have performed interferometric observations of the 12CO (J = 1-0) emission in a sample of 27 objects spanning different evolutionary stages from the late asymptotic giant branch (late-AGB), through the post-AGB (pAGB) phase, and to the planetary nebula (PN) stage, but dominated by pAGB objects and young PNs (>=81%). In this paper …
The Optical and Ultraviolet Emission-line Properties of Bright Quasars with Detailed Spectral Energy Distributions
Gu, Qiusheng; Shang, Zhaohui; Brotherton, Michael S. +2 more
We present measurements and statistical properties of the optical and ultraviolet emission lines present in the spectra of 85 bright quasars which have detailed spectral energy distributions. This heterogeneous sample has redshifts up to z = 1.5 and is comprised of three subsamples that may be of particular utility: ultraviolet excess Palomar-Gree…