Science Archives Publication System

AE Aurigae: First Detection of Non-thermal X-Ray Emission from a Bow Shock Produced by a Runaway Star

DOI: 10.1088/2041-8205/757/1/L6 Bibcode: 2012ApJ...757L...6L

Miceli, M.; Bonito, R.; Romero, G. E. +6 more

Runaway stars produce shocks when passing through interstellar medium at supersonic velocities. Bow shocks have been detected in the mid-infrared for several high-mass runaway stars and in radio waves for one star. Theoretical models predict the production of high-energy photons by non-thermal radiative processes in a number sufficiently large to …

2012 • The Astrophysical Journal

XMM-Newton 32

Episodic bright and dark spots on Uranus

DOI: 10.1016/j.icarus.2012.04.009 Bibcode: 2012Icar..220....6S

Sromovsky, L. A.; Fry, P. M.; Hueso, R. +14 more

The northern mid-latitudes of Uranus produce greater episodes of bright cloud formation than any other region on the planet. Near 30°N, very bright cloud features were observed in 1999, 2004, and 2005, with lifetimes of the order of months. In October 2011, Gemini and HST observations revealed another unusually bright cloud feature near 23°N, whic…

2012 • Icarus

eHST 32

GK Per (Nova Persei 1901): Hubble Space Telescope Imagery and Spectroscopy of the Ejecta, and First Spectrum of the Jet-like Feature

DOI: 10.1088/0004-6256/143/6/143 Bibcode: 2012AJ....143..143S

Livio, Mario; De Marco, Orsola; Shara, Michael M. +3 more

We have imaged the ejecta of GK Persei (Nova Persei 1901 A.D.) with the Hubble Space Telescope (HST), whose 0.1 arcsec resolution reveals hundreds of cometary-like structures with long axes aligned toward GK Per. One or both ends of the structures often show a brightness enhancement relative to the structures' middle sections, but there is no simp…

2012 • The Astronomical Journal

eHST 32

Near-infrared spectroscopy of gamma-ray burst host galaxies at z %≳ 1.5: insights into host galaxy dynamics and interpretations of afterglow absorption spectra

DOI: 10.1111/j.1365-2966.2011.19944.x Bibcode: 2012MNRAS.419.3039C

Chen, Hsiao-Wen

This paper presents near-infrared echellette spectra of faint galaxies in the fields around GRB 050820A at redshift z= 2.613 and GRB 060418 at z= 1.490. The spectroscopic data show that both gamma-ray bursts (GRBs) originate in a dynamic environment of interacting galaxies separated by <15 h^-1 kpc in projected distance and |Δv| ≲ 60 …

2012 • Monthly Notices of the Royal Astronomical Society

eHST 32

New X-Ray Detections of WNL Stars

DOI: 10.1088/0004-6256/143/5/116 Bibcode: 2012AJ....143..116S

Skinner, Stephen L.; Zhekov, Svetozar A.; Güdel, Manuel +2 more

Previous studies have demonstrated that putatively single nitrogen-type Wolf-Rayet stars (WN stars) without known companions are X-ray sources. However, almost all WN star X-ray detections so far have been of earlier WN2-WN6 spectral subtypes. Later WN7-WN9 subtypes (also known as WNL stars) have proved more difficult to detect, an important excep…

2012 • The Astronomical Journal

XMM-Newton 32

The northern hemisphere of asteroid (21) Lutetia—topography and orthoimages from Rosetta OSIRIS NAC image data

DOI: 10.1016/j.pss.2012.01.008 Bibcode: 2012P&SS...66...54P

Mottola, Stefano; Roatsch, Thomas; Matz, Klaus-Dieter +5 more

During the flyby at asteroid (21) Lutetia by the Rosetta spacecraft in July 2010, the OSIRIS imaging system onboard acquired several hundred images of Lutetia's surface. Images of the OSIRIS NAC (Narrow Angle Camera) comprise up to 60 m/pixel ground resolution. We analyzed 84 multi-spectral NAC images with stereo-photogrammetric methods. A 3D poin…

2012 • Planetary and Space Science

Rosetta 32

Direct Measurement of the X-Ray Time-delay Transfer Function in Active Galactic Nuclei

DOI: 10.1088/0004-637X/760/1/73 Bibcode: 2012ApJ...760...73L

Turner, T. J.; Kraemer, S. B.; Reeves, J. N. +3 more

The origin of the observed time lags, in nearby active galactic nuclei (AGNs), between hard and soft X-ray photons is investigated using new XMM-Newton data for the narrow-line Seyfert I galaxy Ark 564 and existing data for 1H 0707-495 and NGC 4051. These AGNs have highly variable X-ray light curves that contain frequent, high peaks of emission. T…

2012 • The Astrophysical Journal

XMM-Newton 32

Upper limits for H ₂SO ₄ in the mesosphere of Venus

DOI: 10.1016/j.icarus.2011.03.032 Bibcode: 2012Icar..217..839S

Moriarty-Schieven, Gerald; Clancy, R. Todd; Sandor, Brad J.

Rapid temporal variability of SO ₂ and SO in the Venus 85-100 km mesosphere ( Sandor, B.J., Clancy, R.T., Moriarty-Schieven G.H. [2007]. Bull. Am. Astron. Soc. 39, 503; Sandor, B.J., Clancy, R.T., Moriarty-Schieven, G.H., Mills, F.P. [2010]. Icarus 208, 49-60) requires in situ sources and sinks for these molecules. While many loss mecha…

2012 • Icarus

VenusExpress 32

A new super-soft X-ray source in the Small Magellanic Cloud: Discovery of the first Be/white dwarf system in the SMC?

DOI: 10.1051/0004-6361/201117789 Bibcode: 2012A&A...537A..76S

Pietsch, W.; Haberl, F.; Mereghetti, S. +5 more

Context. The Small Magellanic Cloud (SMC) hosts a large number of Be/X-ray binaries, however no Be/white dwarf system is known so far, although population synthesis calculations predict that they might be more frequent than Be/neutron star systems.
Aims: XMMU J010147.5-715550 was found as a new faint super-soft X-ray source (SSS) with a likel…

2012 • Astronomy and Astrophysics

XMM-Newton 32

Spectroscopic Confirmation of a z = 6.740 Galaxy behind the Bullet Cluster

DOI: 10.1088/2041-8205/755/1/L7 Bibcode: 2012ApJ...755L...7B

Fontana, Adriano; Stiavelli, Massimo; Treu, Tommaso +7 more

We present the first results of our spectroscopic follow-up of 6.5 < z < 10 candidate galaxies behind clusters of galaxies. We report the spectroscopic confirmation of an intrinsically faint Lyman break galaxy (LBG) identified as a z _850LP-band dropout behind the Bullet Cluster. We detect an emission line at λ = 9412 Å at >5σ s…

2012 • The Astrophysical Journal

eHST 32