Search Publications
Star-Galaxy Classification in Multi-band Optical Imaging
Hogg, David W.; Fadely, Ross; Willman, Beth
Ground-based optical surveys such as PanSTARRS, DES, and LSST will produce large catalogs to limiting magnitudes of r >~ 24. Star-galaxy separation poses a major challenge to such surveys because galaxies—even very compact galaxies—outnumber halo stars at these depths. We investigate photometric classification techniques on stars and galaxies w…
A Population of z > 2 Far-infrared Herschel-SPIRE-selected Starbursts
Berta, S.; Magnelli, B.; Lutz, D. +29 more
We present spectroscopic observations for a sample of 36 Herschel-SPIRE 250-500 µm selected galaxies (HSGs) at 2 < z < 5 from the Herschel Multi-tiered Extragalactic Survey. Redshifts are confirmed as part of a large redshift survey of Herschel-SPIRE-selected sources covering ~0.93 deg2 in six extragalactic legacy fields. Ob…
Multiwavelength Observations of V2775 Ori, an Outbursting Protostar in L 1641: Exploring the Edge of the FU Orionis Regime
Henning, Thomas; Manoj, P.; Kounkel, Marina +9 more
Individual outbursting young stars are important laboratories for studying the physics of episodic accretion and the extent to which this phenomenon can explain the luminosity distribution of protostars. We present new and archival data for V2775 Ori (HOPS 223), a protostar in the L 1641 region of the Orion molecular clouds that was discovered by …
Flare-generated Type II Burst without Associated Coronal Mass Ejection
Zhukov, A. N.; Magdalenić, J.; Vršnak, B. +2 more
We present a study of the solar coronal shock wave on 2005 November 14 associated with the GOES M3.9 flare that occurred close to the east limb (S06° E60°). The shock signature, a type II radio burst, had an unusually high starting frequency of about 800 MHz, indicating that the shock was formed at a rather low height. The position of the radio so…
The Birth of an Ultraluminous X-Ray Source in M83
Soria, Roberto; Blair, William P.; Whitmore, Bradley C. +4 more
A previously undetected (LX < 1036 erg s-1) source in the strongly star-forming galaxy M83 entered an ultraluminous state between 2009 August and 2010 December. It was first seen with Chandra on 2010 December 23 at LX ≈ 4 × 1039 erg s-1 and has remained ultraluminous through our …
The ACS Nearby Galaxy Survey Treasury. X. Quantifying the Star Cluster Formation Efficiency of nearby Dwarf Galaxies
Johnson, L. Clifton; Fouesneau, Morgan; Seth, Anil C. +6 more
We study the relationship between the field star formation and cluster formation properties in a large sample of nearby dwarf galaxies. We use optical data from the Hubble Space Telescope and from ground-based telescopes to derive the ages and masses of the young (t age <~ 100 Myr) cluster sample. Our data provide the first constrain…
A Constant Limiting Mass Scale for Flat Early-type Galaxies from z ~ 1 to z = 0: Density Evolves but Shapes Do Not
Franx, Marijn; van der Wel, Arjen; Rix, Hans-Walter +1 more
We measure the evolution in the intrinsic shape distribution of early-type galaxies from z ~ 1 to z ~ 0 by analyzing their projected axis-ratio distributions. We extract a low-redshift sample (0.04 < z < 0.08) of early-type galaxies with very low star formation rates from the Sloan Digital Sky Survey, based on a color-color selection scheme …
Optical and Infrared Photometry of Globular Clusters in NGC 1399: Evidence for Color-Metallicity Nonlinearity
Jordán, Andrés; Peng, Eric W.; Ferrarese, Laura +3 more
We combine new Wide Field Camera 3 IR Channel (WFC3/IR) F160W (H 160) imaging data for NGC 1399, the central galaxy in the Fornax cluster, with archival F475W (g 475), F606W (V 606), F814W (I 814), and F850LP (z 850) optical data from the Advanced Camera for Surveys (ACS). The purely optical g…
Unveiling the Physical Properties and Kinematics of Molecular Gas in the Antennae Galaxies (NGC 4038/9) through High-resolution CO (J = 3-2) Observations
Tamura, Yoichi; Wilson, Christine D.; Yun, Min S. +12 more
We present a ~1'' (100 pc) resolution 12CO (3-2) map of the nearby intermediate-stage interacting galaxy pair NGC 4038/9 (the Antennae galaxies) obtained with the Submillimeter Array. We find that half the CO (3-2) emission originates in the overlap region where most of the tidally induced star formation had been previously found in sho…
Early-type Galaxies at z = 1.3. I. The Lynx Supercluster: Cluster and Groups at z = 1.3. Morphology and Color-Magnitude Relation
White, Richard L.; Illingworth, Garth D.; Koyama, Yusei +18 more
We confirm the detection of three groups in the Lynx supercluster, at z ≈ 1.3, through spectroscopic follow-up and X-ray imaging, and we give estimates for their redshifts and masses. We study the properties of the group galaxies compared to the two central clusters, RX J0849+4452 and RX J0848+4453. Using spectroscopic follow-up and multi-waveleng…