Search Publications
The hot gas content of fossil galaxy clusters
Arnaud, M.; Pointecouteau, E.; Pratt, G. W. +1 more
We investigate the properties of the hot gas in four fossil galaxy systems detected at high significance in the Planck Sunyaev-Zeldovich (SZ) survey. XMM-Newton observations reveal overall temperatures of kT ~ 5-6 keV and yield hydrostatic masses M500,HE ≳ 3.5 × 1014M⊙, confirming their nature as bona fide massive …
Multiwavelength campaign on Mrk 509. XV. Global modeling of the broad emission lines in the optical, UV, and X-ray bands
Kaastra, J. S.; Arav, N.; Bianchi, S. +11 more
Aims: We model the broad emission lines present in the optical, UV, and X-ray spectra of Mrk 509, a bright type 1 Seyfert galaxy. The broad lines were simultaneously observed during a large multiwavelength campaign, using the XMM-Newton-OM for the optical lines, HST-COS for the UV lines, and XMM-Newton-RGS and Epic for the X-ray lines. We als…
The slowly pulsating B-star 18 Pegasi: A testbed for upper main sequence stellar evolution
Mugrauer, M.; Irrgang, A.; Moehler, S. +2 more
The predicted width of the upper main sequence in stellar evolution models depends on the empirical calibration of the convective overshooting parameter. Despite decades of discussions, its precise value is still unknown and further observational constraints are required to gauge it. Based on a photometric and preliminary asteroseismic analysis, w…
Particle dynamics in a non-flaring solar active region model
Parnell, C. E.; Neukirch, T.; Threlfall, J. +1 more
Aims: The aim of this work is to investigate and characterise particle behaviour in an (observationally-driven) 3D magnetohydrodynamic (MHD) model of the solar atmosphere above a slowly evolving, non-flaring active region.
Methods: We use a relativistic guiding-centre particle code to investigate the behaviour of selected particle orbits…
On the accretion process in a high-mass star forming region. A multitransitional THz Herschel-HIFI study of ammonia toward G34.26+0.15
Menten, K. M.; Persson, C. M.; Olberg, M. +8 more
Aims: Our aim is to explore the gas dynamics and the accretion process in the early phase of high-mass star formation.
Methods: The inward motion of molecular gas in the massive star forming region G34.26+0.15 is investigated by using high-resolution profiles of seven transitions of ammonia at THz frequencies observed with Herschel-HIFI.…
The 2015 outburst of the accreting millisecond pulsar IGR J17511-3057 as seen by INTEGRAL, Swift, and XMM-Newton
Torres, D. F.; Romano, P.; Ferrigno, C. +5 more
We report on INTEGRAL, Swift, and XMM-Newton observations of IGR J17511-3057 performed during the outburst that occurred between March 23 and April 25, 2015. The source reached a peak flux of 0.7(2) × 10-9 erg cm-2 s-1 and decayed to quiescence in approximately a month. The X-ray spectrum was dominated by a power l…
Planck's Dusty GEMS. II. Extended [CII] emission and absorption in the Garnet at z = 3.4 seen with ALMA
Kneissl, R.; Le Floc'h, E.; Falgarone, E. +9 more
We present spatially resolved ALMA [CII] observations of the bright (flux density S350 = 400 mJy at 350 µm), gravitationally lensed, starburst galaxy PLCK G045.1+61.1 at z = 3.427, the "Garnet". This source is part of our set of "Planck's Dusty GEMS", discovered with the Planck's all-sky survey. Two emission-line clouds with a rel…
X-ray and optical spectroscopy of the massive young open cluster IC 1805
Nazé, Y.; Rauw, G.
Context. Very young open clusters are ideal places to study the X-ray properties of a homogeneous population of early-type stars. In this respect, the IC 1805 open cluster is very interesting as it hosts the O4 If+ star HD 15570 thought to be in an evolutionary stage intermediate between a normal O-star and a Wolf-Rayet star.
Aims:…
Triangulum galaxy viewed by Planck
Chemin, L.; Nucita, A. A.; De Paolis, F. +9 more
We used Planck data to study the M 33 galaxy and find a substantial temperature asymmetry with respect to its minor axis projected onto the sky plane. This temperature asymmetry correlates well with the HI velocity field at 21 cm, at least within a galactocentric distance of 0.5°, and it is found to extend up to about 3° from the galaxy center. We…
Herschel/HIFI observations of the circumstellar ammonia lines in IRC+10216
Menten, K. M.; Olofsson, H.; Marston, A. P. +14 more
Context. A discrepancy exists between the abundance of ammonia (NH3) derived previously for the circumstellar envelope (CSE) of
Aims: To address the discrepancy described above…