Search Publications
The ACS LCID Project. IX. Imprints of the Early Universe in the Radial Variation of the Star Formation History of Dwarf Galaxies
Skillman, Evan D.; Dolphin, Andrew; Monelli, Matteo +8 more
Based on Hubble Space Telescope observations from the Local Cosmology from Isolated Dwarfs project, we present the star formation histories, as a function of galactocentric radius, of four isolated Local Group dwarf galaxies: two dSph galaxies, Cetus and Tucana, and two transition galaxies (dTrs), LGS-3 and Phoenix. The oldest stellar populations …
Properties of a Solar Flare Kernel Observed by Hinode and SDO
Young, P. R.; Doschek, G. A.; Warren, H. P. +1 more
Flare kernels are compact features located in the solar chromosphere that are the sites of rapid heating and plasma upflow during the rise phase of flares. An example is presented from a M1.1 class flare in active region AR 11158 observed on 2011 February 16 07:44 UT for which the location of the upflow region seen by EUV Imaging Spectrometer (EIS…
Physical Properties of Spectroscopically Confirmed Galaxies at z >= 6. I. Basic Characteristics of the Rest-frame UV Continuum and Lyα Emission
Ouchi, Masami; Shimasaku, Kazuhiro; Fan, Xiaohui +8 more
We present deep Hubble Space Telescope near-IR and Spitzer mid-IR observations of a large sample of spectroscopically confirmed galaxies at z >= 6. The sample consists of 51 Lyα emitters (LAEs) at z ~= 5.7, 6.5, and 7.0, and 16 Lyman break galaxies (LBGs) at 5.9 <= z <= 6.5. The near-IR images were mostly obtained with WFC3 in the F125W a…
Central Stellar Mass Deficits in the Bulges of Local Lenticular Galaxies, and the Connection with Compact z ~ 1.5 Galaxies
Graham, Alister W.; Dullo, Bililign T.
We have used the full radial extent of images from the Hubble Space Telescope's Advanced Camera for Surveys and Wide Field Planetary Camera 2 to extract surface brightness profiles from a sample of six, local lenticular galaxy candidates. We have modeled these profiles using a core-Sérsic bulge plus an exponential disk model. Our fast rotating len…
Revealing the Heavily Obscured Active Galactic Nucleus Population of High-redshift 3CRR Sources with Chandra X-Ray Observations
Wilkes, Belinda J.; Fazio, G. G.; Ogle, Patrick +12 more
Chandra observations of a complete, flux-limited sample of 38 high-redshift (1 < z < 2), low-frequency-selected (and so unbiased in orientation) 3CRR radio sources are reported. The sample includes 21 quasars (=broad-line radio galaxies) and 17 narrow-line radio galaxies (NLRGs) with matched 178 MHz radio luminosity (log L R(5 GHz…
Mean Age Gradient and Asymmetry in the Star Formation History of the Small Magellanic Cloud
Anderson, J.; Cignoni, M.; Tosi, M. +5 more
We derive the star formation history (SFH) in four regions of the Small Magellanic Cloud (SMC) using the deepest VI color-magnitude diagrams (CMDs) ever obtained for this galaxy. The images were obtained with the Advanced Camera for Surveys on board the Hubble Space Telescope (HST) and are located at projected distances of 0.°5-2° from the SMC cen…
Discovery of Fe Kα X-Ray Reverberation around the Black Holes in MCG-5-23-16 and NGC 7314
Fabian, A. C.; Miniutti, G.; Cackett, E. M. +3 more
Several X-ray observations have recently revealed the presence of reverberation time delays between spectral components in active galactic nuclei. Most of the observed lags are between the power-law Comptonization component, seen directly, and the soft excess produced by reflection in the vicinity of the black hole. NGC 4151 was the first object t…
Mapping H-band Scattered Light Emission in the Mysterious SR21 Transitional Disk
Henning, Thomas; Terada, Hiroshi; Usuda, Tomonori +50 more
We present the first near infrared (NIR) spatially resolved images of the circumstellar transitional disk around SR21. These images were obtained with the Subaru HiCIAO camera, adaptive optics, and the polarized differential imaging technique. We resolve the disk in scattered light at H-band for stellocentric 0.''1 <= r <= 0.''6 (12 <~ r …
Contamination of Broadband Photometry by Nebular Emission in High-redshift Galaxies: Investigations with Keck's MOSFIRE Near-infrared Spectrograph
Stark, Daniel P.; Ellis, Richard S.; Konidaris, Nick P. +1 more
Earlier work has raised the potential importance of nebular emission in the derivation of the physical characteristics of high-redshift Lyman break galaxies. Within certain redshift ranges, and especially at z ~= 6-7, such lines may be strong enough to reduce estimates of the stellar masses and ages of galaxies compared with those derived assuming…
Multi-wavelength SEDs of Herschel-selected Galaxies in the COSMOS Field
Berta, S.; Riguccini, L.; Casey, Caitlin M. +15 more
We combine Herschel Photodetector Array Camera and Spectrometer and Spectral and Photometric Imaging Receiver maps of the full 2 deg2 Cosmic Evolution Survey (COSMOS) field with existing multi-wavelength data to obtain template and model-independent optical-to-far-infrared spectral energy distributions (SEDs) for 4218 Herschel-selected …