Search Publications
Massive stars in the giant molecular cloud G23.3-0.3 and W41
Menten, Karl M.; Rich, R. Michael; MacKenty, John W. +7 more
Context. Young massive stars and stellar clusters continuously form in the Galactic disk, generating new Hii regions within their natal giant molecular clouds and subsequently enriching the interstellar medium via their winds and supernovae.
Aims: Massive stars are among the brightest infrared stars in such regions; their identification permi…
Proper motions for HST observations in three off-axis bulge fields
Rich, R. M.; Soto, M.; Kuijken, K. +3 more
Aims: This is the second in a series of papers that attempt to unveil the kinematic structure of the Galactic bulge through studying radial velocities and proper motions. We report here ~15 000 new proper motions for three low foreground-extinction off-axis fields of the Galactic bulge.
Methods: Proper motions were derived from a combina…
Understanding the dynamical structure of pulsating stars. HARPS spectroscopy of the δ Scuti stars ρ Puppis and DX Ceti
Guiglion, G.; Poretti, E.; Rainer, M. +4 more
Context. High-resolution spectroscopy is a powerful tool to study the dynamical structure of a pulsating star's atmosphere.
Aims: We aim at comparing the line asymmetry and velocity of the two δ Sct stars ρ Pup and DX Cet with previous spectroscopic data obtained on classical Cepheids and β Cep stars.
Methods: We obtained, analysed and d…
A dynamical transition from atomic to molecular intermediate-velocity clouds
Boulanger, F.; Lagache, G.; Kerp, J. +2 more
Context. Towards the high galactic latitude sky, the far-infrared (FIR) intensity is tightly correlated to the total hydrogen column density which is made up of atomic (H i) and molecular hydrogen (H2). Above a certain column density threshold, atomic hydrogen turns molecular.
Aims: We analyse gas and dust properties of intermediat…
First detection of [N II] 205 µm absorption in interstellar gas. Herschel-HIFI observations towards W 31C, W 49N, W 51, and G34.3+0.1
Menten, K. M.; Falgarone, E.; Levrier, F. +8 more
We present high resolution [N ii] 205 µm (3P1 - 3P0) spectra obtained with Herschel-HIFI towards a small sample of far-infrared bright star forming regions in the Galactic plane: W 31C (G10.6-0.4), W 49N (G43.2-0.1), W 51 (G49.5-0.4), and G34.3+0.1. All sources display an emission line profile asso…
Ammonia observations in the LBV nebula G79.29+0.46. Discovery of a cold ring and some warm spots
Palau, Aina; Henkel, C.; Rizzo, J. R. +1 more
Context. The surroundings of luminous blue variable (LBV) stars are excellent laboratories to study the effects of their high UV radiation, powerful winds, and strong ejection events onto the surrounding gas and dust.
Aims: We aim at determining the physical parameters of the dense gas near G79.29+0.46, an LBV-candidate located at the centre …
Traveling solar-wind bulk-velocity fluctuations and their effects on electron heating in the heliosphere
Verscharen, Daniel; Fahr, Hans J.; Chashei, Igor V.
Ambient plasma electrons undergo strong heating in regions associated with compressive bulk-velocity jumps ΔU that travel through the interplanetary solar wind. The heating is generated by their specific interactions with the jump-inherent electric fields. After this energy gain is thermalized by the shock passage through the operation of the Bune…
Pre-perihelion activity of comet 67P/Churyumov-Gerasimenko
Schulz, R.; Tozzi, G. P.; Rożek, A. +3 more
Context. Comets are believed to hold a relatively pristine record of the physical and chemical processes that occurred during the formation and evolution of the solar system. Thorough investigations of these small bodies, such as the one that will be performed by the ESA/Rosetta cornerstone mission, are thus supposed to bring strong and unique con…
Ionization structure of multiple-shell planetary nebulae. I. NGC 2438
Zijlstra, A. A.; Öttl, S.; Kimeswenger, S.
Context. In recent times an increasing number of extended haloes and multiple shells around planetary nebulae have been discovered. These faint extensions to the main nebula trace the mass-loss history of the star, modified by the subsequent evolution of the nebula. Integrated models predict that some haloes may be recombining, and thus are not in…
Listening to galaxies tuning at z ~ 2.5-3.0: The first strikes of the Hubble fork
Cimatti, A.; Halliday, C.; Mignoli, M. +4 more
Aims: We investigate the morphological properties of 494 galaxies selected from the Galaxy Mass Assembly ultra-deep Spectroscopic Survey (GMASS) at z > 1, primarily in their optical rest frame, using Hubble Space Telescope (HST) infrared images, from the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS).
Methods: The …