Search Publications
Star Formation Activity in the Long, Filamentary Infrared Dark Cloud G53.2
Koo, Bon-Chul; Kim, Hyun-Jeong; Davis, Christopher J.
We present star formation activity in the infrared dark cloud (IRDC) G53.2, a remarkable IRDC located at Galactic coordinates (l,b)∼ (53\buildrel{\circ}\over{.} 2, 0\buildrel{\circ}\over{.} 0) based on the census of young stellar object (YSO) candidates. IRDC G53.2 was previously identified as several IRDCs in mid-IR images, but it is in fact a lo…
The Cheshire Cat Gravitational Lens: The Formation of a Massive Fossil Group
White, Raymond E., III; Maksym, W. Peter; Dupke, Renato +3 more
The Cheshire Cat is a relatively poor group of galaxies dominated by two luminous elliptical galaxies surrounded by at least four arcs from gravitationally lensed background galaxies that give the system a humorous appearance. Our combined optical/X-ray study of this system reveals that it is experiencing a line of sight merger between two groups …
Host Galaxy Properties and Black Hole Mass of Swift J164449.3+573451 from Multi-wavelength Long-term Monitoring and HST Data
Urata, Yuji; Sakamoto, Takanori; Im, Myungshin +6 more
We study the host galaxy properties of the tidal disruption object Swift J164449.3+573451 using long-term optical to near-infrared (NIR) data. First, we decompose the galaxy surface brightness distribution and analyze the morphology of the host galaxy using high-resolution Hubble Space Telescope WFC3 images. We conclude that the host galaxy is bul…
The Transitional Disk around IRAS 04125+2902
Andrews, S.; Wilner, D.; Espaillat, C. +4 more
Resolved submillimeter imaging of transitional disks is increasingly revealing the complexity of disk structure. Here, we present the first high-resolution submillimeter image of a recently identified transitional disk around IRAS 04125+2902 in the Taurus star-forming region. We measure an inner disk hole of ∼20 AU around IRAS 04125+2902 by simult…
Discovery of Collimated Bipolar Outflows in the Planetary Nebula Th 2-A
Danehkar, A.
We present a comprehensive set of spatially resolved, integral field spectroscopic mapping of the Wolf-Rayet planetary nebula Th 2-A, obtained using the Wide Field Spectrograph on the Australian National University 2.3-m telescope. Velocity-resolved Hα channel maps with a resolution of 20 km s-1 allow us to identify different kinematic …
Infrared Two-Color Diagrams for AGB Stars, Post-AGB Stars, and Planetary Nebulae
Suh, Kyung-Won
We present various infrared two-color diagrams (2CDs) for asymptotic giant branch (AGB) stars, post-AGB stars, and Planetary Nebulae (PNe) and investigate possible evolutionary tracks. We use catalogs from the available literature for the sample of 4903 AGB stars (3373 O-rich; 1168 C-rich; 362 S-type), 660 post-AGB stars (326 post-AGB; 334 pre-PN)…
A Search for Population III Galaxies in CLASH. I. Singly-imaged Candidates at High Redshift
Östlin, Göran; Melinder, Jens; Zitrin, Adi +6 more
Population III (Pop III) galaxies are predicted to exist at high redshifts and may be rendered sufficiently bright for detection with current telescopes when gravitationally lensed by a foreground galaxy cluster. Pop III galaxies that exhibit strong Lyα emission should furthermore be identifiable from broadband photometry because of their unusual …
Broadband X-Ray Spectral Investigations of Magnetars, 4U 0142+61, 1E 1841-045,1E 2259+586, AND 1E 1048.1-5937
Göğüş, Ersin; Weng, Shan-Shan
We have generated an extended version of a rather simplified but physically oriented three-dimensional magnetar emission model, STEMS3D, to allow spectral investigations up to 100 keV. We then applied our model to the broadband spectra of four magnetars: 4U 0142+61, 1E 1841-045, 1E 2259+586, and 1E 1048.1-5937, using data collected with Swift/XRT …
Magnesium-rich Ejecta in the SNR G284.3-1.8 Around the High-mass Gamma-Ray Binary 1FGL J1018.6-5856
Pavlov, George G.; Kargaltsev, Oleg; Rangelov, Blagoy +1 more
We present results from two Chandra observations of the 16.6 day X-ray/γ-ray high-mass binary 1FGL J1018.6-5856 located at the center of the supernova remnant (SNR) G284.3-1.8. The binary spectra, separated by 0.25 in binary phase, are fit with an absorbed power-law model with {{Γ }}≈ 1.7-1.8 for both observations (the flux during the second obser…
Two Populations of Old Star Clusters in the Spiral Galaxy M101 Based on HST/ACS Observations
Whitmore, Bradley C.; Chandar, Rupali; Simanton, Lesley A.
We present a new photometric catalog of 326 candidate globular clusters (GCs) in the nearby spiral galaxy M101, selected from B, V, and I Hubble Space Telescope Advanced Camera for Surveys images. The luminosity function (LF) of these clusters has an unusually large number of faint sources compared with GCLFs in many other spiral galaxies. Accordi…