Science Archives Publication System

Detection of VHE gamma-ray emission from the distant blazar 1ES 1101-232 with HESS and broadband characterisation

DOI: 10.1051/0004-6361:20077057 Bibcode: 2007A&A...470..475A

Santangelo, A.; Ripken, J.; Carrigan, S. +122 more

Context: The blazar 1ES 1101-232 was observed with the High Energy Stereoscopic System (HESS) of Atmospheric Cherenkov Telescopes (ACT) in 2004 and 2005, for a live time of 43 h. VHE (E > 10¹¹ eV) γ-rays were detected for the first time from this object.
Aims: VHE observations of blazars are used to investigate…

2007 • Astronomy and Astrophysics

XMM-Newton 132

SPI observations of the diffuse ⁶⁰Fe emission in the Galaxy

DOI: 10.1051/0004-6361:20066982 Bibcode: 2007A&A...469.1005W

Wang, W.; Strong, A. W.; Knödlseder, J. +12 more

Aims:Gamma-ray line emission from radioactive decay of ⁶⁰Fe provides constraints on nucleosynthesis in massive stars and supernovae.
Methods: spectrometer SPI on board INTEGRAL has accumulated nearly three years of data on gamma-ray emission from the Galactic plane. We have analyzed these data with suitable instrumental-background m…

2007 • Astronomy and Astrophysics

INTEGRAL 132

The Signature of Primordial Grain Growth in the Polarized Light of the AU Microscopii Debris Disk

DOI: 10.1086/509318 Bibcode: 2007ApJ...654..595G

Matthews, Brenda C.; Graham, James R.; Kalas, Paul G.

We have used the Hubble Space Telescope Advanced Camera for Surveys coronagraph to make the first polarization maps of the AU Microscopii debris disk. The polarization rises from 5% at 20 AU to 40% at 80 AU. The polarization is perpendicular to the disk, indicating that the scattered light originates from micron-sized grains in an optically thin d…

2007 • The Astrophysical Journal

eHST 131

Low-luminosity active galactic nuclei: are they UV faint and radio loud?

DOI: 10.1111/j.1365-2966.2007.11735.x Bibcode: 2007MNRAS.377.1696M

Maoz, Dan

Low-luminosity active galactic nuclei (AGNs) are perceived to be radio loud and devoid of a `big blue bump', indicating a transition from a radiatively efficient, geometrically thin, accretion disc in high-luminosity AGNs, to a geometrically thick, radiatively inefficient accretion flow at low luminosities and accretion rates. I revisit the issue …

2007 • Monthly Notices of the Royal Astronomical Society

eHST 131

Cosima High Resolution Time-of-Flight Secondary Ion Mass Spectrometer for the Analysis of Cometary Dust Particles onboard Rosetta

DOI: 10.1007/s11214-006-9083-0 Bibcode: 2007SSRv..128..823K

Langevin, Y.; Altwegg, K.; Krüger, H. +38 more

The ESA mission Rosetta, launched on March 2nd, 2004, carries an instrument suite to the comet 67P/Churyumov-Gerasimenko. The COmetary Secondary Ion Mass Anaylzer - COSIMA - is one of three cometary dust analyzing instruments onboard Rosetta. COSIMA is based on the analytic measurement method of secondary ion mass spectrometry (SIMS). The experime…

2007 • Space Science Reviews

Rosetta 130

Magnetic hydrogen atmosphere models and the neutron star RX J1856.5-3754

DOI: 10.1111/j.1365-2966.2006.11376.x Bibcode: 2007MNRAS.375..821H

Ho, Wynn C. G.; Kaplan, David L.; Chang, Philip +2 more

RX J1856.5-3754 is one of the brightest nearby isolated neutron stars (INSs), and considerable observational resources have been devoted to it. However, current models are unable to satisfactorily explain the data. We show that our latest models of a thin, magnetic, partially ionized hydrogen atmosphere on top of a condensed surface can fit the en…

2007 • Monthly Notices of the Royal Astronomical Society

XMM-Newton eHST 130

The Hα surges and EUV jets from magnetic flux emergences and cancellations

DOI: 10.1051/0004-6361:20053954 Bibcode: 2007A&A...469..331J

Yang, L. H.; Li, K. J.; Jiang, Y. C. +2 more

We analyzed multi-wavelength observations of three surges with a recurrent period of about 70 min in Hα, EUV, and soft X-ray, which occurred in the quiet-sun region on 2000 November 3. These homologous surges were associated with small flares at the same base, but their exact footpoints were spatially separated from the flare. Each surge consisted…

2007 • Astronomy and Astrophysics

SOHO 130

Internal Properties of Ultracompact Dwarf Galaxies in the Virgo Cluster

DOI: 10.1086/511958 Bibcode: 2007AJ....133.1722E

Hilker, M.; Evstigneeva, E. A.; Drinkwater, M. J. +1 more

We present new imaging and spectroscopic observations of six ultracompact dwarf (UCD) galaxies in the Virgo Cluster, along with reanalyzed data for five Fornax Cluster UCDs. These are the most luminous UCDs: -14 mag < M_V < -12 mag. Our Hubble Space Telescope imaging shows that most of the UCDs have shallow or steep cusps in their …

2007 • The Astronomical Journal

eHST 130

X-Ray Absorption from the Milky Way Halo and the Local Group

DOI: 10.1086/521321 Bibcode: 2007ApJ...669..990B

Bregman, Joel N.; Lloyd-Davies, Edward J.

Million degree gas is present at near-zero redshift and is due to either a gaseous Galactic halo or a more diffuse but very massive Local Group medium. We can discriminate between these models because the column densities should depend on location in the sky, either relative to the Galaxy bulge or to the M31-Milky Way axis. To search for these sig…

2007 • The Astrophysical Journal

XMM-Newton 130

Constraining supernova models using the hot gas in clusters of galaxies

DOI: 10.1051/0004-6361:20066382 Bibcode: 2007A&A...465..345D

Kaastra, J. S.; de Plaa, J.; Vink, J. +3 more

Context: The hot X-ray emitting gas in clusters of galaxies is a very large repository of metals produced by supernovae. During the evolution of clusters, billions of supernovae eject their material into this Intra-Cluster Medium (ICM).
Aims: We aim to accurately measure the abundances in the ICM of many clusters and compare these data with me…

2007 • Astronomy and Astrophysics

XMM-Newton 130