Search Publications
Grain size limits derived from 3.6 µm and 4.5 µm coreshine
Juvela, M.; Paladini, R.; Henning, Th. +8 more
Context. Recently discovered scattered light from molecular cloud cores in the wavelength range 3-5 µm (called "coreshine") seems to indicate the presence of grains with sizes above 0.5 µm.
Aims: We aim to analyze 3.6 and 4.5 µm coreshine from molecular cloud cores to probe the largest grains in the size distribution.
M…
A morpho-kinematic and spectroscopic study of the bipolar nebulae: M 2-9, Mz 3, and Hen 2-104
Akras, S.; Steffen, W.; Harvey, E. +3 more
Context. Complex bipolar shapes can be generated either as a planetary nebula or a symbiotic system. The origin of the material ionised by the white dwarf is very different in these two scenarios, and it complicates the understanding of the morphologies of planetary nebulae.
Aims: The physical properties, structure, and dynamics of the bipola…
X-ray spectral variability of Seyfert 2 galaxies
González-Martín, O.; Márquez, I.; Masegosa, J. +1 more
Context. Variability across the electromagnetic spectrum is a property of active galactic nuclei (AGN) that can help constrain the physical properties of these galaxies. Nonetheless, the way in which the changes happen and whether they occur in the same way in every AGN are still open questions.
Aims: This is the third in a series of papers w…
Abundance and temperature distributions in the hot intra-cluster gas of Abell 4059
Zhang, Y. -Y.; Simionescu, A.; Kaastra, J. S. +5 more
Using the EPIC and RGS data from a deep (200 ks) XMM-Newton observation, we investigate the temperature structure (kT and σT) and the abundances of nine elements (O, Ne, Mg, Si, S, Ar, Ca, Fe, and Ni) of the intra-cluster medium (ICM) in the nearby (z = 0.046) cool-core galaxy cluster Abell 4059. Next to a deep analysis of the cluster c…
Planck intermediate results. XXVI. Optical identification and redshifts of Planck clusters with the RTT150 telescope
Böhringer, H.; Kneissl, R.; Dahle, H. +197 more
We present the results of approximately three years of observations of Planck Sunyaev-Zeldovich (SZ) sources with the Russian-Turkish 1.5 m telescope (RTT150), as a part of the optical follow-up programme undertaken by the Planck collaboration. During this time period approximately 20% of all dark and grey clear time available at the telescope was…
Spectroscopically resolved far-IR observations of the massive star-forming region G5.89-0.39
Menten, K. M.; Levrier, F.; Gerin, M. +9 more
Context. The fine-structure line of atomic oxygen at 63 µm ([OI]63µm) is an important diagnostic tool in different fields of astrophysics: it is for example predicted to be the main coolant in several environments of star-forming regions (SFRs). However, our knowledge of this line relies on observations with low spectral res…
The Lyman alpha reference sample. IV. Morphology at low and high redshift
Schaerer, D.; Östlin, G.; Hayes, M. +21 more
Context. The transport of Lyα photons in galaxies is a complex process and the conditions under which Lyα photons manage to escape from certain galaxies is still under investigation. The Lyman alpha reference sample (LARS) is a sample of 14 local star-forming galaxies, designed to study Lyα in detail and relate it to rest-frame UV and optical emis…
The hidden quasar nucleus of a WISE-selected, hyperluminous, dust-obscured galaxy at z ~ 2.3
Maiolino, R.; Fiore, F.; Bianchi, S. +8 more
We present the first X-ray spectrum of a hot dust-obscured galaxy (DOG), namely W1835+4355 at z ~ 2.3. Hot DOGs represent a very rare population of hyperluminous (≥1047 erg s-1), dust-enshrouded objects at z ≥ 2 recently discovered in the WISE All Sky Survey. The 40 ks XMM-Newton spectrum reveals a continuum as flat (Γ ~ 0.8)…
ALMA observations of anisotropic dust mass loss in the inner circumstellar environment of the red supergiant VY Canis Majoris
Kervella, P.; Decin, L.; Richards, A. M. S. +8 more
The processes leading to dust formation and the subsequent role it plays in driving mass loss in cool evolved stars is an area of intense study. Here we present high resolution ALMA Science Verification data of the continuum emission around the highly evolved oxygen-rich red supergiant VY CMa. These data enable us to study the dust in its inner ci…
The two-colour EMCCD instrument for the Danish 1.54 m telescope and SONG
Christensen-Dalsgaard, J.; Andersen, M. F.; Grundahl, F. +13 more
We report on the implemented design of a two-colour instrument based on electron-multiplying CCD (EMCCD) detectors. This instrument is currently installed at the Danish 1.54 m telescope at ESO's La Silla Observatory in Chile, and will be available at the SONG (Stellar Observations Network Group) 1m telescope node at Tenerife and at other SONG node…