Search Publications
Water abundance variations around high-mass protostars: HIFI observations of the DR21 region
de Graauw, Th.; Liseau, R.; Braine, J. +56 more
Context. Water is a key molecule in the star formation process, but its spatial distribution in star-forming regions is not well known.
Aims: We study the distribution of dust continuum and H2O and 13CO line emission in DR21, a luminous star-forming region with a powerful outflow and a compact H ii region.
Methods: …
The double-peaked 2008 outburst of the accreting milli-second X-ray pulsar, IGR J00291+5934
Bloom, J. S.; Wijnands, R.; Russell, D. M. +18 more
Context. In August 2008, the accreting milli-second X-ray pulsar (AMXP), IGR J00291+5934, underwent an outburst lasting ~100 days, the first since its discovery in 2004.
Aims: We present data from the 2008 double-peaked outburst of IGR J00291+5934 from Faulkes Telescope North, the Isaac Newton Telescope, the Keck Telescope, PAIRITEL, the West…
Herschel observations of the hydroxyl radical (OH) in young stellar objects
de Graauw, Th.; Liseau, R.; Braine, J. +59 more
Aims: “Water In Star-forming regions with Herschel” (WISH) is a Herschel key program investigating the water chemistry in young stellar objects (YSOs) during protostellar evolution. Hydroxyl (OH) is one of the reactants in the chemical network most closely linked to the formation and destruction of H2O. High-temperature (T ⪆ 250 K)…
Mapping far-IR emission from the central kiloparsec of NGC 1097
Helou, G.; Roussel, H.; Murphy, E. J. +39 more
Using photometry of NGC 1097 from the Herschel PACS (Photodetector Array Camera and Spectrometer) instrument, we study the resolved properties of thermal dust continuum emission from a circumnuclear starburst ring with a radius ~900 pc. These observations are the first to resolve the structure of a circumnuclear ring at wavelengths that probe the …
Transiting exoplanets from the CoRoT space mission. XII. CoRoT-12b: a short-period low-density planet transiting a solar analog star
Mazeh, T.; Aigrain, S.; Alonso, R. +50 more
We report the discovery by the CoRoT satellite of a new transiting giant planet in a 2.83 days orbit about a V = 15.5 solar analog star (M_* = 1.08 ± 0.08 M_⊙, R_* = 1.1 ± 0.1 R_⊙, Teff = 5675 ± 80 K). This new planet, CoRoT-12b, has a mass of 0.92 ± 0.07 MJup and a radius of 1.44 ± 0.13 RJup. Its low density can b…
Herschel observations of ortho- and para-oxidaniumyl (H2O+) in spiral arm clouds toward Sagittarius B2(M)
Menten, K. M.; Falgarone, E.; Martin, P. G. +56 more
H2O+ has been observed in its ortho- and para- states toward the massive star forming core Sgr B2(M), located close to the Galactic center. The observations show absorption in all spiral arm clouds between the Sun and Sgr B2. The average o/p ratio of H2O+ in most velocity intervals is 4.8, which correspo…
First detection of the Sunyaev Zel'dovich effect increment at λ < 650 µm
Kneib, J. -P.; Smith, G. P.; Lutz, D. +28 more
The Sunyaev-Zel'dovich (SZ) effect is a spectral distortion of the cosmic microwave background as observed through the hot plasma in galaxy clusters. This distortion is a decrement in the CMB intensity for λ > 1.3 mm, an increment at shorter wavelengths, and small again by λ ~ 250 µm. As part of the Herschel Lensing Survey (HLS) we have m…
Non-thermal radio emission from O-type stars. IV. Cygnus OB2 No. 8A
Blomme, R.; Rauw, G.; Volpi, D. +1 more
Context. Several early-type colliding-wind binaries are known to emit synchrotron radiation due to relativistic electrons, which are most probably accelerated by the Fermi mechanism. By studying such systems we can learn more about this mechanism, which is also relevant in other astrophysical contexts. Colliding-wind binaries are furthermore impor…
Silicon in the dust formation zone of IRC +10216
Ivison, R. J.; Blommaert, J. A. D. L.; Olofsson, G. +36 more
The interstellar medium is enriched primarily by matter ejected from evolved low and intermediate mass stars. The outflows from these stars create a circumstellar envelope in which a rich gas-phase and dust-nucleation chemistry takes place. We observed the nearest carbon-rich evolved star, IRC +10216, using the PACS (55-210 µm) and SPIRE (19…
Gas morphology and energetics at the surface of PDRs: New insights with Herschel observations of NGC 7023
Boulanger, F.; Martin, P. G.; France, K. +37 more
Context. We investigate the physics and chemistry of the gas and dust in dense photon-dominated regions (PDRs), along with their dependence on the illuminating UV field.
Aims: Using Herschel/HIFI observations, we study the gas energetics in NGC 7023 in relation to the morphology of this nebula. NGC 7023 is the prototype of a PDR illuminated b…