Search Publications
Mid-infrared Determination of Total Infrared Luminosity and Star Formation Rates of Local and High-redshift Galaxies
Kartaltepe, J. S.; Rujopakarn, W.; Rieke, G. H. +4 more
We demonstrate estimating the total infrared luminosity, L(TIR), and star formation rates (SFRs) of star-forming galaxies at redshift 0 < z < 2.8 from single-band 24 µm observations, using local spectral energy distribution (SED) templates without introducing additional free parameters. Our method is based on characterizing the SEDs of…
Structural Evolution of Early-type Galaxies to z = 2.5 in CANDELS
Bell, Eric F.; Ferguson, Henry C.; Grogin, Norman A. +18 more
Projected axis ratio measurements of 880 early-type galaxies at redshifts 1 < z < 2.5 selected from CANDELS are used to reconstruct and model their intrinsic shapes. The sample is selected on the basis of multiple rest-frame colors to reflect low star-formation activity. We demonstrate that these galaxies as an ensemble are dust-poor and tra…
Chemical Evolution in High-mass Star-forming Regions: Results from the MALT90 Survey
Hoq, Sadia; Jackson, James M.; Foster, Jonathan B. +7 more
The chemical changes of high-mass star-forming regions provide a potential method for classifying their evolutionary stages and, ultimately, ages. In this study, we search for correlations between molecular abundances and the evolutionary stages of dense molecular clumps associated with high-mass star formation. We use the molecular line maps from…
Twist Accumulation and Topology Structure of a Solar Magnetic Flux Rope
Cheng, X.; Ding, M. D.; Guo, Y. +2 more
To study the buildup of a magnetic flux rope before a major flare and coronal mass ejection (CME), we compute the magnetic helicity injection, twist accumulation, and topology structure of the three-dimensional (3D) magnetic field, which is derived by the nonlinear force-free field model. The Extreme-ultraviolet Imaging Telescope on board the Sola…
Fossil Imprint of a Powerful Flare at the Galactic Center along the Magellanic Stream
Sutherland, Ralph S.; Bland-Hawthorn, J.; Maloney, Philip R. +1 more
The Fermi satellite discovery of the gamma-ray emitting bubbles extending 50° (10 kpc) from the Galactic center has revitalized earlier claims that our Galaxy has undergone an explosive episode in the recent past. We now explore a new constraint on such activity. The Magellanic Stream is a clumpy gaseous structure free of stars trailing behind the…
Physical Properties of Spectroscopically Confirmed Galaxies at z >= 6. II. Morphology of the Rest-frame UV Continuum and Lyα Emission
Ouchi, Masami; Shimasaku, Kazuhiro; Fan, Xiaohui +8 more
We present a detailed structural and morphological study of a large sample of spectroscopically confirmed galaxies at z >= 6 using deep Hubble Space Telescope (HST) near-IR broad-band images and Subaru Telescope optical narrow-band images. The galaxy sample consists of 51 Lyα emitters (LAEs) at z ~= 5.7, 6.5, and 7.0, and 16 Lyman break galaxie…
The Rise of an Ionized Wind in the Narrow-line Seyfert 1 Galaxy Mrk 335 Observed by XMM-Newton and HST
Kriss, G. A.; Ely, J.; Komossa, S. +6 more
We present the discovery of an outflowing ionized wind in the Seyfert 1 galaxy Mrk 335. Despite having been extensively observed by most of the largest X-ray observatories in the last decade, this bright source was not known to host warm absorber gas until recent XMM-Newton observations in combination with a long-term Swift monitoring program have…
Testing the Universality of the Fundamental Metallicity Relation at High Redshift Using Low-mass Gravitationally Lensed Galaxies
Richard, Johan; Ellis, Richard S.; Belli, Sirio +1 more
We present rest-frame optical spectra for a sample of nine low-mass star-forming galaxies in the redshift range 1.5 < z < 3 which are gravitationally lensed by foreground clusters. We used Triplespec, an echelle spectrograph at the Palomar 200 inch telescope that is very effective for this purpose as it samples the entire near-infrared spect…
X-Ray Properties of the Northern Galactic Cap Sources in the 58 Month Swift/BAT Catalog
Brandt, William N.; Mushotzky, Richard F.; Baumgartner, Wayne H. +5 more
We present a detailed X-ray spectral analysis of the non-beamed, hard X-ray selected active galactic nuclei (AGNs) in the northern Galactic cap of the 58 month Swift Burst Alert Telescope (Swift/BAT) catalog, consisting of 100 AGNs with b > 50°. This sky area has excellent potential for further dedicated study due to a wide range of multi-wavel…
A High-resolution Spectroscopic Search for the Remaining Donor for Tycho's Supernova
Anderson, Jay; Filippenko, Alexei V.; Foley, Ryan J. +12 more
In this paper, we report on our analysis using Hubble Space Telescope astrometry and Keck-I HIRES spectroscopy of the central six stars of Tycho's supernova remnant (SN 1572). With these data, we measured the proper motions, radial velocities, rotational velocities, and chemical abundances of these objects. Regarding the chemical abundances, we do…