Search Publications
The Stellar Mass-Halo Mass Relation for Low-mass X-Ray Groups At 0.5< z< 1 in the CDFS With CSI
Kelson, Daniel D.; McCarthy, Patrick J.; Dressler, Alan +4 more
Since z∼ 1, the stellar mass density locked in low-mass groups and clusters has grown by a factor of ∼8. Here, we make the first statistical measurements of the stellar mass content of low-mass X-ray groups at 0.5\lt z\lt 1, enabling the calibration of stellar-to-halo mass scales for wide-field optical and infrared surveys. Groups are selected fro…
Modeling of Hot Plasma in the Solar Active Region Core
Schmelz, J. T.; Pathak, S.; Imada, S. +2 more
Magnetically confined plasma with temperatures ≥slant 5 {MK} are a feature of hot coronal loops observed in the core of active regions. In this paper, using observations and MHD modeling of coronal loops, we investigate whether wave heating (Alternating Current) models can describe the high temperature loops observed in the active region of 2012 S…
Two Candidate Optical Counterparts of M82 X-1 from HST Observations
Liu, Jifeng; Bai, Yu; Wang, Song +1 more
Optical counterparts can provide significant constraints on the physical nature of ultraluminous X-ray sources (ULXs). In this Letter, we identify six point sources in the error circle of a ULX in M82, namely M82 X-1, by registering Chandra positions onto Hubble Space Telescope images. Two objects are considered as optical counterpart candidates o…
Mass and Energy of Erupting Solar Plasma Observed with the X-Ray Telescope on Hinode
Moon, Yong-Jae; Reeves, Katharine K.; Raymond, John C. +2 more
We investigate seven eruptive plasma observations by Hinode/XRT. Their corresponding EUV and/or white light coronal mass ejection features are visible in some events. Five events are observed in several passbands in X-rays, which allows for the determination of the eruptive plasma temperature using a filter ratio method. We find that the isotherma…
The High-velocity System: Infall of a Giant Low-surface-brightness Galaxy toward the Center of the Perseus Cluster
Ohyama, Youichi; Broadhurst, T.; Lim, Jeremy +2 more
The high-velocity system (HVS) lies just north-west of the center and is moving at a speed of 3000 km s-1 toward NGC 1275, the central giant elliptical galaxy in the Perseus cluster. We report imaging spectroscopy of the HVS in Hα and [N ii] that resolves both the nature of this galaxy and its physical relationship with NGC 1275. The HV…
The Young Stellar Object Population in the Vela-D Molecular Cloud
Elia, D.; Pezzuto, S.; Molinari, S. +7 more
We investigate the young stellar population in the Vela Molecular Ridge, Cloud-D, a star-forming region observed by both the Spitzer/NASA and Herschel/ESA space telescopes. The point-source, band-merged, Spitzer-IRAC catalog complemented with MIPS photometry previously obtained is used to search for candidate young stellar objects (YSOs), also inc…
The Evolved Main-sequence Channel: HST and LBT Observations of CSS120422:111127+571239
Szkody, P.; Garnavich, P.; Kennedy, M. +3 more
The “evolved main-sequence (EMS)” channel is thought to contribute significantly to the population of AM CVn-type systems in the Galaxy, and also to the number of cataclysmic variables (CVs) detected below the period minimum for hydrogen rich systems. CSS 120422:J111127+571239 was discovered by the Catalina Sky Survey in 2012 April. Its period was…
LEGUS Discovery of a Light Echo Around Supernova 2012aw
Van Dyk, Schuyler D.; Anderson, Jay; Grebel, Eva K. +9 more
We have discovered a luminous light echo around the normal Type II-Plateau Supernova (SN) 2012aw in Messier 95 (M95; NGC 3351), detected in images obtained approximately two years after explosion with the Wide Field Channel 3 on board the Hubble Space Telescope by the Legacy ExtraGalactic Ultraviolet Survey. The multi-band observations span from t…
HST/WFC3 Observations of an Off-nuclear Superbubble in Arp 220
Kewley, Lisa J.; Lu, Jessica R.; Heckman, Timothy M. +9 more
We present a high spatial resolution optical and infrared study of the circumnuclear region in Arp 220, a late-stage galaxy merger. Narrowband imaging using Hubble Space Telescope/WFC3 has resolved the previously observed peak in Hα+[N ii] emission into a bubble-shaped feature. This feature measures 1.″6 in diameter, or 600 pc, and is only 1″ nort…
Tracing the Metal-poor M31 Stellar Halo with Blue Horizontal Branch Stars
Bell, Eric F.; Williams, Benjamin F.; Gilbert, Karoline M. +8 more
We have analyzed new Hubble Space Telescope (HST)/Advanced Camera for Surveys and HST/WFC3 imaging in F475W and F814W of two previously unobserved fields along the M31 minor axis to confirm our previous constraints on the shape of M31's inner stellar halo. Both of these new data sets reach a depth of at least F814W <27 and clearly detect the bl…