Search Publications
The Faint-End Slopes of Galaxy Luminosity Functions in the COSMOS Field
Mobasher, Bahram; Capak, Peter; Rich, R. Michael +5 more
We examine the faint-end slope of the rest-frame V-band luminosity function (LF), with respect to galaxy spectral type, of field galaxies with redshift z < 0.5, using a sample of 80,820 galaxies with photometric redshifts in the 2 deg2 Cosmic Evolution Survey (COSMOS) field. For all galaxy spectral types combined, the LF slope ranges…
Photoevaporation of Protoplanetary Disks
Rieke, George H.; Bally, John; Gáspár, András +4 more
We present HST NICMOS Paschen α (Paα) images and low- and high-resolution IRS spectra of photoevaporating disk-tail systems originally detected at 24 µm near O stars. We find no Paα emission in any of the systems. The resulting upper limits correspond to about (2-3) × 10-6 M⊙ of mass in hydrogen in the tails, suggesting…
Investigation into the Subsurface Magnetic Structure in an Emerging Flux Region on the Sun Based on a Comparison between Hinode's Observations and Numerical Simulations
Magara, T.
In this Letter we report a result of investigating the structure of subsurface magnetic field in an emerging flux region on the Sun, which was observed by Hinode. The data obtained by Hinode captured well the structure end evolution of the emerging flux region, showing the appearance of small magnetic features that lead to a well-developed bipolar…
PSR J0737-3039: Interacting Pulsars in X-Rays
Tiengo, A.; Mereghetti, S.; Esposito, P. +2 more
We present the results of a ~230 ks long X-ray observation of the relativistic double-pulsar system PSR J0737-3039 obtained with the XMM-Newton satellite in 2006 October. We confirm the detection in X-rays of pulsed emission from PSR J0737-3039A (PSR A), mostly ascribed to a soft nonthermal power-law component (Γ ~ 3.3) with a 0.2-3 keV luminosity…
XMM-Newton, Chandra, and CGPS observations of the Supernova Remnants G85.4+0.7 and G85.9-0.6
Jackson, M. S.; Safi-Harb, S.; Kothes, R. +1 more
We present an XMM-Newton detection of two low radio surface brightness supernova remnants (SNRs), G85.4+0.7 and G85.9-0.6, discovered with the Canadian Galactic Plane Survey (CGPS). High-resolution XMM-Newton images revealing the morphology of the diffuse emission, as well as discrete point sources, are presented and correlated with radio and Chan…
The Structure of the DoAr 25 Circumstellar Disk
Wilner, D. J.; Andrews, Sean M.; Qi, Chunhua +1 more
We present high spatial resolution (lsim 0.3'' ≈ 40 AU) Submillimeter Array observations of the 865 µm continuum emission from the circumstellar disk around the young star DoAr 25. Despite its bright millimeter emission, this source exhibits only a comparatively small infrared excess and low accretion rate, suggesting that the material and s…
The Lack of Strong O-Line Excess in the Coma Cluster Outskirts from Suzaku
Miller, Eric D.; Bregman, Joel N.; Ohashi, Takaya +6 more
About half of the baryons in the local universe are thought to reside in the so-called warm-hot intergalactic medium (WHIM) at temperatures of 0.1-10 MK. Thermal soft excess emission in the spectrum of some cluster outskirts that contains O VII and/or O VIII emission lines is regarded as evidence of the WHIM, although the origin of the lines is co…
Magnetic Twist of EUV Coronal Loops Well-traced in TRACE Images: Evidence for Magnetic Reconnection Origin of Coronal Loops?
Chae, Jongchul; Kwon, Ryun Young
The measurements of magnetic twist of EUV coronal loops for 14 loops are presented here. EUV coronal loops are thin, EUV-emitting structures of hot plasma tracing magnetic field lines in the corona. The constriction of plasma into a loop without dispersion may be explained if the magnetic field of the loop is twisted. On the basis of this idea, Ch…
Hubble Space Telescope Images of Red Mergers: How Dry Are They?
van Dokkum, Pieter G.; Whitaker, Katherine E.
Mergers between red galaxies are observed to be common in the nearby universe, and are thought to be the dominant mechanism by which massive galaxies grow their mass at late times. These "dry" mergers can be readily identified in very deep ground-based images, thanks to their extended low surface brightness tidal features. However, ground-based im…
Observation of an Extended Very High Energy Gamma-Ray Emission from MSH 15-52 with CANGAROO-III
Katagiri, H.; Edwards, P. G.; Gunji, S. +46 more
We have observed the supernova remnant MSH 15-52 (G320.4-1.2), which contains the gamma-ray pulsar PSR B1509-58, using the CANGAROO-III imaging atmospheric Cerenkov telescope array from 2006 April to June. We detected gamma rays above 810 GeV at the 7 σ level during a total effective exposure of 48.4 hr. We obtained a differential gamma-ray flux a…