Search Publications
Slow magnetosonic waves detected in reconnection diffusion region in the Earth's magnetotail
Zhang, T. L.; Dandouras, I.; Cao, J. B. +4 more
We studied the ULF waves with a period of 30 s in the ion diffusion region of reconnection observed by Cluster satellites on 21 August 2002. The fast convective tailward ion flow accompanied with a large southward magnetic field component, a strong Hall magnetic field, and a Hall electric field demonstrates that the Cluster satellites are located …
Broad iron line in the fast spinning neutron-star system 4U 1636-53
Hiemstra, Beike; Belloni, Tomaso; Méndez, Mariano +3 more
We analysed the X-ray spectra of six observations, simultaneously taken with XMM-Newton and Rossi X-ray Timing Explorer (RXTE), of the neutron-star low-mass X-ray binary 4U 1636-53. The observations cover several states of the source, and therefore a large range of inferred mass accretion rate. These six observations show a broad emission line in …
The Role of Merger Stage on Galaxy Radio Spectra in Local Infrared-bright Starburst Galaxies
Murphy, Eric J.
An investigation of the steep, high-frequency (i.e., ν ~ 12 GHz) radio spectra among a sample of 31 local infrared-bright starburst galaxies is carried out in light of their Hubble-Space-Telescope-based merger classifications. Radio data covering as many as 10 individual bands allow for spectral indices to be measured over three frequency bins bet…
OH far-infrared emission from low- and intermediate-mass protostars surveyed with Herschel-PACS
van Dishoeck, E. F.; Larsson, B.; Goicoechea, J. R. +10 more
Context. The OH radical is a key species in the water chemistry network of star-forming regions, because its presence is tightly related to the formation and destruction of water. Previous studies of the OH far-infrared emission from low- and intermediate-mass protostars suggest that the OH emission mainly originates from shocked gas and not from …
Herschel far-infrared observations of the Carina Nebula complex. II. The embedded young stellar and protostellar population
Preibisch, T.; Zinnecker, H.; Roccatagliata, V. +3 more
Context. The Carina Nebula represents one of the largest and most active star forming regions known in our Galaxy. It contains numerous very massive (M ≳ 40 M⊙) stars that strongly affect the surrounding clouds by their ionizing radiation and stellar winds.
Aims: Our recently obtained Herschel PACS and SPIRE far-infrared maps cover…
Precision Measurement of The Most Distant Spectroscopically Confirmed Supernova Ia with the Hubble Space Telescope
Huang, X.; Wang, L.; Lidman, C. +26 more
We report the discovery of a redshift 1.71 supernova in the GOODS-North field. The Hubble Space Telescope (HST) ACS spectrum has almost negligible contamination from the host or neighboring galaxies. Although the rest-frame-sampled range is too blue to include any Si II line, a principal component analysis allows us to confirm it as a Type Ia supe…
Herschel-HIFI observations of high-J CO and isotopologues in star-forming regions: from low to high mass
Braine, J.; van Dishoeck, E. F.; Johnstone, D. +9 more
Context. Our understanding of the star formation process has traditionally been confined to certain mass or luminosity boundaries because most studies focus only on low-, intermediate-, or high-mass star-forming regions. Therefore, the processes that regulate the formation of these different objects have not been effectively linked. As part of the…
PSR J0357+3205: The Tail of the Turtle
Belfiore, A.; Marelli, M.; Saz Parkinson, P. M. +6 more
Using a new XMM-Newton observation, we have characterized the X-ray properties of the middle-aged radio-quiet γ-ray pulsar J0357+3205 (named Morla) and its tail. The X-ray emission from the pulsar is consistent with a magnetospheric non-thermal origin plus a thermal emission from a hot spot (or hot spots). The lack of a thermal component from the …
Vertical broad-line region structure in nearby active galactic nuclei
Kollatschny, W.; Zetzl, M.
Context. Broad emission lines are emitted in the surroundings of supermassive black holes in the centers of active galactic nuclei (AGN). This region is spatially not resolved.
Aims: We intend to get information on the structure and geometry of this broad emitting line region based on line profile observations.
Methods: We model the rota…
Calculating Time Lags from Unevenly Sampled Light Curves
Cackett, E. M.; Zoghbi, A.; Reynolds, C.
Timing techniques are powerful tools to study dynamical astrophysical phenomena. In the X-ray band, they offer the potential of probing accretion physics down to the event horizon. Recent work has used frequency- and energy-dependent time lags as tools for studying relativistic reverberation around the black holes in several Seyfert galaxies. This…