Search Publications
Strong lensing as a probe of the mass distribution beyond the Einstein radius. Mass and light in SL2S J08544-0121, a galaxy group at z = 0.35
Kneib, J. -P.; Jullo, E.; Gavazzi, R. +6 more
Strong lensing has been employed extensively to obtain accurate mass measurements within the Einstein radius. We here use strong lensing to probe mass distributions beyond the Einstein radius. We consider SL2S J08544-0121, a galaxy group at redshift z=0.35 with a bimodal light distribution and with a strong lensing system located at one of the two…
LoCuSS: Shedding new light on the massive lensing cluster Abell 1689 - the view from Herschel
Smith, G. P.; Egami, E.; Rex, M. +5 more
We present wide-field Herschel/PACS observations of A 1689, a massive galaxy cluster at z = 0.1832, from our open time key programme. We detect 39 spectroscopically confirmed 100 µm-selected cluster members down to 1.5×1010 L⊙. These galaxies are forming stars at rates in the range 1-10 M⊙/yr, and appear to c…
Hard X-ray identification of η Carinae and steadiness close to periastron
Walter, R.; Rauw, G.; Leyder, J. -C.
Context. The colliding-wind binary η Carinae exhibits soft X-ray thermal emission that varies strongly around the periastron passage. It has been found to have non-thermal emission, thanks to its detection in hard X-rays using INTEGRAL and Suzaku, and also in γ-rays with AGILE and Fermi.
Aims: This paper attempts to definitively identify η Ca…
Hier ist wahrhaftig ein Loch im Himmel. The NGC 1999 dark globule is not a globule
Maret, S.; Henning, T.; Manoj, P. +22 more
The NGC 1999 reflection nebula features a dark patch with a size of 10 000 AU, which has been interpreted as a small, dense foreground globule and possible site of imminent star formation. We present Herschel PACS far-infrared 70 and 160 µm maps, which reveal a flux deficit at the location of the globule. We estimate the globule mass needed …
Detection of the high z GRB 080913 and its implications on progenitors and energy extraction mechanisms
Bremer, M.; Jóhannesson, G.; Pérez-Ramírez, D. +15 more
Aims: We present multiwavelength observations of one of the most distant gamma-ray bursts detected so far, GRB 080913. Based on these observations, we consider whether it could be classified as a short-duration GRB and discuss the implications for the progenitor nature and energy extraction mechanisms.
Methods: Multiwavelength X-ray, nea…
Multiwavelength observations of a giant flare on CN Leonis. III. Temporal evolution of coronal properties
Liefke, C.; Schmitt, J. H. M. M.; Fuhrmeister, B.
Context. Stellar flares affect all atmospheric layers from the photosphere over chromosphere and transition region up into the corona. Simultaneous observations in different spectral bands allow to obtain a comprehensive picture of the environmental conditions and the physical processes going on during different phases of the flare.
Aims: We …
Swift follow-up observations of 13 INTEGRAL sources
Tomsick, J. A.; Rodriguez, J.; Bodaghee, A.
The various IBIS/ISGRI catalogues contain a large population of hard X-ray sources whose nature is still unknown. Even if the >20 keV positional uncertainty provided by ISGRI is unprecedented, it is still too large to pinpoint the counterpart at other wavelengths, which is the only secure way of obtaining a source identification. We continue th…
A characterization of the NGC 4051 soft X-ray spectrum as observed by XMM-Newton
Bianchi, S.; Guainazzi, M.; Santos-Lleo, M. +3 more
Context. Soft X-ray high resolution spectroscopy of obscured AGNs shows a complex soft X-ray spectrum dominated by emission lines of He and H-like transitions of elements from carbon to neon, as well as L-shell transitions due to iron ions.
Aims: In this paper we characterize the XMM-Newton RGS spectrum of the Seyfert 1 galaxy NGC 4051 observ…
A few days before the end of the 2008 extreme outburst of EX Lupi: accretion shocks and a smothered stellar corona unveiled by XMM-Newton
Hamaguchi, K.; Grosso, N.; Kastner, J. H. +2 more
Context. EX Lup is a pre-main sequence star that exhibits repetitive and irregular optical outbursts driven by an increase in the mass accretion rate in its circumstellar disk. In mid-January 2008, EX Lup, the prototype of the small class of eruptive variables called EXors, began an extreme outburst that lasted seven months.
Aims: We attempt …
Herschel-PACS far-infrared photometry of two z > 4 quasars
Meisenheimer, K.; Jean, C.; Walter, F. +14 more
We present Herschel far-infrared (FIR) observations of two sub-mm bright quasars at high redshift: SDSS J1148+5251 (z = 6.42) and BR 1202-0725 (z = 4.69) obtained with the PACS instrument. Both objects are detected in the PACS photometric bands. The Herschel measurements provide additional data points that constrain the FIR spectral energy distrib…