Science Archives Publication System

The Evolution of Galaxies in X-Ray-luminous Groups

DOI: 10.1086/511852 Bibcode: 2007ApJ...658..865J

Mulchaey, John S.; Fassnacht, Christopher D.; Lubin, Lori M. +1 more

We investigate the galaxy populations in seven X-ray-selected, intermediate-redshift groups (0.2<z<0.6). Overall, the galaxy populations in these systems are similar to those in clusters at the same redshift; they have large fractions of early-type galaxies (f_e~70%) and small fractions of galaxies with significant star formation (…

2007 • The Astrophysical Journal

eHST 48

Exploring the connection between the stellar wind and the non-thermal emission in LS 5039

DOI: 10.1051/0004-6361:20077508 Bibcode: 2007A&A...473..545B

Motch, C.; Janot-Pacheco, E.; Negueruela, I. +5 more

Context: LS 5039 has been observed with several X-ray instruments so far showing quite steady emission in the long term and no signatures of accretion disk. The source also presents X-ray variability at orbital timescales in flux and photon index. The system harbors an O-type main sequence star with moderate mass-loss. At present, the link between…

2007 • Astronomy and Astrophysics

XMM-Newton 48

The Spatio-Kinematical Structure and Distance of the Preplanetary Nebula IRAS 19134+2131

DOI: 10.1086/521350 Bibcode: 2007ApJ...669..424I

Sahai, Raghvendra; Morris, Mark; Imai, Hiroshi

Using the Very Long Baseline Array at six epochs, we have observed H₂O maser emission in the preplanetary nebula IRAS 19134+2131 (I19134), in which the H₂O maser spectrum has two groups of emission features separated in radial velocity by ~100 km s^-1. We also obtained optical images of I19134 with the Hubble Space …

2007 • The Astrophysical Journal

eHST 48

Spitzer Observations of Transient, Extended Dust in Two Elliptical Galaxies: New Evidence of Recent Feedback Energy Release in Galactic Cores

DOI: 10.1086/520123 Bibcode: 2007ApJ...666..222T

Brighenti, Fabrizio; Mathews, William G.; Temi, Pasquale

Spitzer observations of extended dust in two optically normal elliptical galaxies provide a new confirmation of buoyant feedback outflow in the hot gas atmospheres around these galaxies. AGN feedback energy is required to prevent wholesale cooling and star formation in these group-centered galaxies. In NGC 5044 we observe interstellar (presumably …

2007 • The Astrophysical Journal

eHST 48

Tethys: Lithospheric thickness and heat flux from flexurally supported topography at Ithaca Chasma

DOI: 10.1029/2007GL031467 Bibcode: 2007GeoRL..3421203G

Neukum, Gerhard; Thomas, Peter C.; Helfenstein, Paul +2 more

We have identified flexural uplift along the flanks of Tethys' Ithaca Chasma using Cassini stereo-derived topography. Modeling the topography as a broken elastic plate yields an effective elastic lithospheric thickness in the range of 5-7 km and, combined with the strength envelope of the lithosphere, a mechanical lithospheric thickness of 16-20 k…

2007 • Geophysical Research Letters

Cassini 48

Hard X-ray flares in IGR J08408-4503 unveil clumpy stellar winds

DOI: 10.1051/0004-6361:20066317 Bibcode: 2007A&A...465L..35L

Masetti, N.; Walter, R.; Produit, N. +2 more

Context: A 1000-s flare from a new hard X-ray transient, IGR J08408-4503, was observed by INTEGRAL on May 15, 2006 during the real-time routine monitoring of IBIS/ISGRI images performed at the INTEGRAL Science Data Centre. The flare, detected during a single one-hour long pointing, peaked at 250 mCrab in the 20-40 keV energy ran…

2007 • Astronomy and Astrophysics

INTEGRAL IUE eHST 48

Magnetic Double-Gradient Instability and Flapping Waves in a Current Sheet

DOI: 10.1103/PhysRevLett.99.235003 Bibcode: 2007PhRvL..99w5003E

Semenov, V. S.; Erkaev, N. V.; Biernat, H. K.

A new kind of magnetohydrodynamic instability and waves are analyzed for a current sheet in the presence of a small normal magnetic field component varying along the sheet. These waves and instability are related to the existence of two gradients of the tangential (B_τ) and normal (B_n) magnetic field components along the norma…

2007 • Physical Review Letters

Cluster 47

Motion of flux transfer events: a test of the Cooling model

DOI: 10.5194/angeo-25-1669-2007 Bibcode: 2007AnGeo..25.1669F

Dandouras, I.; Fazakerley, A. N.; Daly, P. W. +7 more

The simple model of reconnected field line motion developed by Cooling et al. (2001) has been used in several recent case studies to explain the motion of flux transfer events across the magnetopause. We examine 213 FTEs observed by all four Cluster spacecraft under a variety of IMF conditions between November 2002 and June 2003, when the spacecra…

2007 • Annales Geophysicae

Cluster 47

Discovery of X-ray burst triplets in EXO 0748-676

DOI: 10.1051/0004-6361:20066204 Bibcode: 2007A&A...465..559B

Boirin, L.; Lewin, W. H. G.; in't Zand, J. J. M. +5 more

Type-I X-ray bursts are thermonuclear flashes that take place on the surface of accreting neutron stars. The wait time between consecutive bursts is set by the time required to accumulate the fuel needed to trigger a new burst; this is at least one hour. Sometimes secondary bursts are observed, approximately 10 min after the main burst. These shor…

2007 • Astronomy and Astrophysics

XMM-Newton 47

Born-Again Protoplanetary Disk around Mira B

DOI: 10.1086/517993 Bibcode: 2007ApJ...662..651I

Lloyd, J. P.; Tuthill, P. G.; Packham, C. +6 more

The Mira AB system is a nearby (~107 pc) example of a wind accreting binary star system. In this class of system, the wind from a mass-losing red giant star (Mira A) is accreted onto a companion (Mira B), as indicated by an accretion shock signature in spectra at ultraviolet and X-ray wavelengths. Using novel imaging techniques, we report the dete…

2007 • The Astrophysical Journal

eHST 47