Search Publications

X-Ray and Radio Follow-up Observations of High-redshift Blazar Candidates in the Fermi-LAT Unassociated Source Population

Kataoka, J.; Maeda, K.; Inoue, S. +6 more

We report on the results of X-ray and radio follow-up observations of two GeV gamma-ray sources 2FGL J0923.5+1508 and 2FGL J1502.1+5548, selected as candidates for high-redshift blazars from unassociated sources in the Fermi Large Area Telescope Second Source Catalog. We utilize the Suzaku satellite and the VLBI Exploration of Radio Astrometry (VE…

Multiwavelength Photometry and Hubble Space Telescope Spectroscopy of the Old Nova V842 Centaurus

Szkody, Paula; Sion, Edward M.; Godon, Patrick +5 more

We present ground-based optical and near infrared photometric observations and Hubble Space Telescope (HST) COS spectroscopic observations of the old nova V842 Cen (Nova Cen 1986). Analysis of the optical light curves reveals a peak at 56.5 ± 0.3 s with an amplitude of 8.9 ± 4.2 mma, which is consistent with the rotation of a magnetic white dwarf …

Is the Large Crater on the Asteroid (2867) Steins Really an Impact Crater?

Burchell, M. J.; Price, M. C.; Morris, A. J. W.

The large crater on the asteroid (2867) Steins attracted much attention when it was first observed by the Rosetta spacecraft in 2008. Initially, it was widely thought to be unusually large compared to the size of the asteroid. It was quickly realized that this was not the case and there are other examples of similar (or larger) craters on small bo…

Chemical and Physical Conditions in Molecular Cloud Core DC 000.4-19.5 (SL42) in Corona Australis

Juvela, M.; Whittet, D. C. B.; Harju, J. +3 more

Chemical reactions in starless molecular clouds are heavily dependent on interactions between gas phase material and solid phase dust and ices. We have observed the abundance and distribution of molecular gases in the cold, starless core DC 000.4-19.5 (SL42) in Corona Australis using data from the Swedish ESO Submillimeter Telescope. We present co…

Discovery of a Large Population of Ultraluminous X-Ray Sources in the Bulgeless Galaxies NGC 337 and ESO 501-23

Mathur, Smita; Martini, Paul; Somers, Garrett +3 more

We have used Chandra observations of eight bulgeless disk galaxies to identify new ultraluminous X-ray source (ULX) candidates, study their high-mass X-ray binary (HMXB) population, and search for low-luminosity active galactic nuclei (AGNs). We report the discovery of 16 new ULX candidates in our sample of galaxies. Eight of these are found in th…

Vertical Relaxation of a Moonlet Propeller in Saturn's A Ring

Seiß, M.; Spahn, F.; Hoffmann, H.

Two images, taken by the Cassini spacecraft near Saturn's equinox in 2009 August, show the Earhart propeller casting a 350 km long shadow, offering the opportunity to watch how the ring height, excited by the propeller moonlet, relaxes to an equilibrium state. From the shape of the shadow cast and a model of the azimuthal propeller height relaxati…

Detection of an Ultra-bright Submillimeter Galaxy behind the Small Magellanic Cloud

Tamura, Yoichi; Kohno, Kotaro; Yun, Min S. +21 more

We report the discovery of a new ultra-bright submillimeter galaxy (SMG) behind the Small Magellanic Cloud (SMC). This SMG is detected as a 43.3 ± 8.4 mJy point source (MM J01071-7302, hereafter MMJ0107) in the 1.1 mm continuum survey of the SMC by AzTEC on the ASTE telescope. MMJ0107 is also detected in the radio (843 MHz), Herschel/SPIRE, Spitze…

Erratum: "An X-Rays Survey of the Young Stellar Population of the Lynds 1641 and Iota Orionis Regions" (2013, ApJ, 768, 99)

Walter, F.; Micela, G.; Megeath, S. T. +12 more

Moving Objects in the Hubble Ultra Deep Field

Kilic, Mukremin; von Hippel, Ted; Gianninas, Alexandros

We identify proper motion objects in the Hubble Ultra Deep Field (UDF) using the optical data from the original UDF program in 2004 and the near-infrared data from the 128 orbit UDF 2012 campaign. There are 12 sources brighter than I = 27 mag that display >3σ significant proper motions. We do not find any proper motion objects fainter than this…

Spectral Variability of IRAS 18325-5926 and Constraints on the Geometry of the Scattering Medium

Misra, R.; Dewangan, G. C.; Tripathi, Shruti +3 more

We analyze Suzaku and XMM-Newton data of the highly variable Seyfert 2, IRAS 18325-5926. The spectra of the source are well modeled as a primary component described as an absorbed power law and a secondary power-law component which is consistent with being scattered emission from an on-axis extended highly ionized medium. We show that while the pr…