Search Publications
Metal Distributions out to 0.5 r 180 in the Intracluster Medium of Four Galaxy Groups Observed with Suzaku
Sato, Kosuke; Matsushita, Kyoko; Sasaki, Toru
We studied the distributions of metal abundances and metal-mass-to-light ratios in the intracluster medium (ICM) of four galaxy groups, MKW 4, HCG 62, the NGC 1550 group, and the NGC 5044 group, out to ~0.5 r 180 observed with Suzaku. The iron abundance decreases with radius and is about 0.2-0.4 solar beyond 0.1 r 180. At a g…
Early-type Galaxies in the Chandra COSMOS Survey
Civano, F.; Elvis, M.; Pellegrini, S. +4 more
We study a sample of 69 X-ray detected early-type galaxies (ETGs), selected from the Chandra COSMOS survey, to explore the relation between the X-ray luminosity of hot gaseous halos (L X, gas) and the integrated stellar luminosity (LK ) of the galaxies, in a range of redshift extending out to z = 1.5. In the local universe, …
A Multi-instrument Analysis of Sunspot Umbrae
Watson, F. T.; Livingston, W.; Penn, M. J.
The recent solar minimum and rise phase of solar cycle 24 have been unlike any period since the early 1900s. This article examines some of the properties of sunspot umbrae over the last 17 yr with three different instruments on the ground and in space: MDI, HMI and BABO. The distribution of magnetic fields and their evolution over time is shown an…
Understanding the Unique Assembly History of Central Group Galaxies
Treu, Tommaso; Coccato, Lodovico; Leauthaud, Alexie +7 more
Central galaxies (CGs) in massive halos live in unique environments with formation histories closely linked to that of the host halo. In local clusters, they have larger sizes (Re ) and lower velocity dispersions (σ) at fixed stellar mass M *, and much larger Re at a fixed σ than field and satellite galaxies (non-C…
3D-HST Emission Line Galaxies at z ~ 2: Discrepancies in the Optical/UV Star Formation Rates
Trump, Jonathan R.; Schneider, Donald P.; Gronwall, Caryl +6 more
We use Hubble Space Telescope near-IR grism spectroscopy to examine the Hβ line strengths of 260 star-forming galaxies in the redshift range 1.90 < z < 2.35. We show that at these epochs, the Hβ star formation rate (SFR) is a factor of ~1.8 higher than what would be expected from the systems' rest-frame UV flux density, suggesting a shift in…
Patchy Accretion Disks in Ultra-luminous X-Ray Sources
Harrison, F. A.; Fabian, A. C.; Miller, J. M. +5 more
The X-ray spectra of the most extreme ultra-luminous X-ray sources—those with L >= 1040 erg s-1—remain something of a mystery. Spectral roll-over in the 5-10 keV band was originally detected in the deepest XMM-Newton observations of the brightest sources; this is confirmed in subsequent NuSTAR spectra. This emission can be…
Multi-wavelength High-resolution Observations of a Small-scale Emerging Magnetic Flux Event and the Chromospheric and Coronal Response
Yurchyshyn, Vasyl; Vargas Domínguez, Santiago; Kosovichev, Alexander
State-of-the-art solar instrumentation is now revealing magnetic activity of the Sun with unprecedented temporal and spatial resolutions. Observations with the 1.6 m aperture New Solar Telescope (NST) of the Big Bear Solar Observatory are making next steps in our understanding of the solar surface structure. Granular-scale magnetic flux emergence …
Distribution of Electric Currents in Sunspots from Photosphere to Corona
Gosain, Sanjay; Démoulin, Pascal; López Fuentes, Marcelo
We present a study of two regular sunspots that exhibit nearly uniform twist from the photosphere to the corona. We derive the twist parameter in the corona and in the chromosphere by minimizing the difference between the extrapolated linear force-free field model field lines and the observed intensity structures in the extreme-ultraviolet images …
Discovery of a Strong Lensing Galaxy Embedded in a Cluster at z = 1.62
Koekemoer, Anton M.; Kacprzak, Glenn G.; Tran, Kim-Vy H. +9 more
We identify a strong lensing galaxy in the cluster IRC 0218 (also known as XMM-LSS J02182-05102) that is spectroscopically confirmed to be at z = 1.62, making it the highest-redshift strong lens galaxy known. The lens is one of the two brightest cluster galaxies and lenses a background source galaxy into an arc and a counterimage. With Hubble Spac…
Intermittent Dust Mass Loss from Activated Asteroid P/2013 P5 (PANSTARRS)
Moreno, F.; Licandro, J.; Cabrera-Lavers, A. +2 more
We present observations and models of the dust environment of activated asteroid P/2013 P5 (PANSTARRS). The object displayed a complex morphology during the observations, with the presence of multiple tails. We combined our own observations, all made with instrumentation attached to the 10.4 m Gran Telescopio Canarias on La Palma, with previously …