Search Publications

High-energy emission processes in M87
DOI: 10.1093/mnras/stv927 Bibcode: 2015MNRAS.450.4333D

Tramacere, A.; Beckmann, V.; Soldi, S. +2 more

We study the contribution of thermal and non-thermal processes to the inverse Compton emission of the radio galaxy M87 by modelling its broad-band emission. Through this we aim to derive insight into where within the AGN the X-ray, γ-ray and VHE emission is produced. We have analysed all available INTEGRAL IBIS/ISGRI (Imager on Board INTEGRAL Spac…

2015 Monthly Notices of the Royal Astronomical Society
INTEGRAL Suzaku 20
High spectral and spatial resolution observations of the PDR emission in the NGC 2023 reflection nebula with SOFIA and APEX
DOI: 10.1051/0004-6361/201525881 Bibcode: 2015A&A...578A..41S

Okada, Y.; Güsten, R.; Requena-Torres, M. A. +3 more

We have mapped the NGC 2023 reflection nebula in [C ii] and CO(11-10) with the heterodyne receiver GREAT on SOFIA and obtained slightly smaller maps in 13CO(3-2), CO(3-2), CO(4-3), CO(6-5), and CO(7-6) with APEX in Chile. We use these data to probe the morphology, kinematics, and physical conditions of the C ii region, which is ionized …

2015 Astronomy and Astrophysics
Herschel 20
Relativistic Fe Kα line revealed in the composite X-ray spectrum of narrow-line Seyfert 1 galaxies - do their black holes have averagely low or intermediate spins?
DOI: 10.1093/mnras/stu2423 Bibcode: 2015MNRAS.447..517L

Lu, Youjun; Liu, Zhu; Yuan, Weimin +1 more

While a broad profile of the Fe Kα emission line is frequently found in the X-ray spectra of typical Seyfert galaxies, the situation is unclear in the case of narrow-line Seyfert 1 galaxies (NLS1s) - an extreme subset which are generally thought to harbour less massive black holes with higher accretion rates. In this paper, the ensemble property o…

2015 Monthly Notices of the Royal Astronomical Society
XMM-Newton 20
Internal structure of spiral arms traced with [C II]: Unraveling the warm ionized medium, H I, and molecular emission lanes
DOI: 10.1051/0004-6361/201525902 Bibcode: 2015A&A...578A.135V

Goldsmith, P. F.; Langer, W. D.; Pineda, J. L. +1 more

Context. The spiral arm tangencies are ideal lines of sight in which to determine the distribution of interstellar gas components in the spiral arms and study the influence of spiral density waves on the interarm gas in the Milky Way. [C II] emission in the tangencies delineates the warm ionized component and the photon-dominated regions and is th…

2015 Astronomy and Astrophysics
Herschel 20
Experimental determination of the dispersion relation of magnetosonic waves
DOI: 10.1002/2015JA021746 Bibcode: 2015JGRA..120.9632W

Dandouras, I.; Walker, S. N.; Yearby, K. H. +4 more

Magnetosonic waves are commonly observed in the vicinity of the terrestrial magnetic equator. It has been proposed that within this region they may interact with radiation belt electrons, accelerating some to high energies. These wave-particle interactions depend upon the characteristic properties of the wave mode. Hence, determination of the wave…

2015 Journal of Geophysical Research (Space Physics)
Cluster 20
An empirical approach to modeling ion production rates in Titan's ionosphere I: Ion production rates on the dayside and globally
DOI: 10.1002/2013JA019706 Bibcode: 2015JGRA..120.1264R

Edberg, N. J. T.; Waite, J. H.; Cravens, T. E. +9 more

Titan's ionosphere is created when solar photons, energetic magnetospheric electrons or ions, and cosmic rays ionize the neutral atmosphere. Electron densities generated by current theoretical models are much larger than densities measured by instruments on board the Cassini orbiter. This model density overabundance must result either from overpro…

2015 Journal of Geophysical Research (Space Physics)
Cassini 20
First detections of FS Canis Majoris stars in clusters. Evolutionary state as constrained by coeval massive stars
DOI: 10.1051/0004-6361/201425371 Bibcode: 2015A&A...575A..10D

Najarro, F.; Davies, B.; de la Fuente, D. +2 more

Context. FS CMa stars are low-luminosity objects showing the B[e] phenomenon whose evolutionary state remains a puzzle. These stars are surrounded by compact disks of warm dust of unknown origin. Hitherto, membership of FS CMa stars to coeval populations has never been confirmed.
Aims: The discovery of low-luminosity line emitters in the youn…

2015 Astronomy and Astrophysics
eHST 20
Dispersal of G-band Bright Points at Different Longitudinal Magnetic Field Strengths
DOI: 10.1088/0004-637X/810/2/88 Bibcode: 2015ApJ...810...88Y

Yang, Yunfei; Feng, Song; Wang, Feng +3 more

G-band bright points (GBPs) are thought to be the foot-points of magnetic flux tubes. The aim of this paper is to investigate the relation between the diffusion regimes of GBPs and the associated longitudinal magnetic field strengths. Two high resolution observations of different magnetized environments were acquired with the Hinode/Solar Optical …

2015 The Astrophysical Journal
Hinode 20
A homogeneous analysis of disks around brown dwarfs
DOI: 10.1051/0004-6361/201526153 Bibcode: 2015A&A...582A..22L

Liu, Y.; Bayo, A.; Wang, H. +2 more

We re-analyzed the Herschel/PACS data of a sample of 55 brown dwarfs (BDs) and very low mass stars with spectral types ranging from M5.5 to L0. We investigated the dependence of disk structure on the mass of the central object in the substellar regime based on a homogeneous analysis of Herschel data from flux density measurements to spectral energ…

2015 Astronomy and Astrophysics
Herschel 20
Evolution of Intermittency in the Slow and Fast Solar Wind beyond the Ecliptic Plane
DOI: 10.1088/2041-8205/814/2/L19 Bibcode: 2015ApJ...814L..19W

Bruno, R.; Wawrzaszek, A.; Macek, W. M. +1 more

We study intermittency as a departure from self-similarity of the solar wind magnetic turbulence and investigate the evolution with the heliocentric distance and latitude. We use data from the Ulysses spacecraft measured during two solar minima (1997-1998 and 2007-2008) and one solar maximum (1999-2001). In particular, by modeling a multifractal s…

2015 The Astrophysical Journal
Ulysses 20