Search Publications
[O I] disk emission in the Taurus star-forming region
Woitke, P.; Kamp, I.; Güdel, M. +8 more
Context. The structure of protoplanetary disks is thought to be linked to the temperature and chemistry of their dust and gas. Whether the disk is flat or flaring depends on the amount of radiation that it absorbs at a given radius and on the efficiency with which this is converted into thermal energy. The understanding of these heating and coolin…
Molecules in the transition disk orbiting T Chamaeleontis
Kastner, J. H.; Zuckerman, B.; Forveille, T. +4 more
Aims: We seek to establish the presence and properties of gas in the circumstellar disk orbiting
Methods: We used the Atacama Pathfinder Experiment (APEX) 12 m radiotelescope to search for submillimete…
Kinematic analysis of a sample of X-ray luminous distant galaxy clusters. The LX - σv relation in the z > 0.6 universe
Böhringer, H.; Pratt, G. W.; Rosati, P. +11 more
Aims: Observations and cosmological simulations show galaxy clusters as a family of nearly self-similar objects with properties that can be described by scaling relations as a function of mass and time. Here we study the scaling relations between the galaxy velocity dispersion (σv) and X-ray quantities, such as X-ray bolometric lum…
Discovery of new low-excitation planetary nebulae
Zhang, Yong; Hsia, Chih-Hao
We report a multi-wavelength study of four new planetary nebula (PN) candidates selected from the INT/WFC Photometric Hα Survey of the Northern Galactic Plane (IPHAS) and Deep Sky Hunter (DSH) catalogues. We present mid-resolution optical spectra of these PNs. The PN status of our sample was confirmed by optical narrow-band images and mid-resoluti…
Magnetic pattern at supergranulation scale: the void size distribution
Berrilli, F.; Del Moro, D.; Scardigli, S.
The large-scale magnetic pattern observed in the photosphere of the quiet Sun is dominated by the magnetic network. This network, created by photospheric magnetic fields swept into convective downflows, delineates the boundaries of large-scale cells of overturning plasma and exhibits "voids" in magnetic organization. These voids include internetwo…
A thin diffuse component of the Galactic ridge X-ray emission and heating of the interstellar medium contributed by the radiation of Galactic X-ray binaries
Molaro, Margherita; Khatri, Rishi; Sunyaev, Rashid A.
We predict a thin diffuse component of the Galactic ridge X-ray emission (GRXE) arising from the scattering of the radiation of bright X-ray binaries (XBs) by the interstellar medium. This scattered component has the same scale height as that of the gaseous disk (~80 pc) and is therefore thinner than the GRXE of stellar origin (scale height ~130 p…
Orphan penumbrae: Submerging horizontal fields
Bellot Rubio, L. R.; Jurčák, J.; Sobotka, M.
Aims: We investigate the properties of orphan penumbrae, which are photospheric filamentary structures observed in active regions near polarity inversion lines that resemble the penumbra of regular sunspots but are not connected to any umbra.
Methods: We use Hinode data from the Solar Optical Telescope to determine the properties of orph…
The evolving spectrum of the planetary nebula Hen 2-260
Zijlstra, A. A.; van Hoof, P. A. M.; Hajduk, M. +3 more
Aims: We analysed the planetary nebula Hen 2-260 using optical spectroscopy and photometry. We compared our observations with the data from literature to search for evolutionary changes. We also searched for photomertic variability of the central star.
Methods: The object Hen 2-260 was observed with the SAAO 1.0 m telescope (photometry) …
A state-of-the-art analysis of the dwarf irregular galaxy NGC 6822
Hidalgo, S. L.; Bono, G.; Pietrinferni, A. +5 more
We present a detailed photometric study of the dwarf irregular galaxy NGC 6822 aimed at investigating the properties of its stellar populations and, in particular, the presence of stellar radial gradients. Our goal is to analyse the stellar populations in six fields, which cover the whole bar of this dwarf galaxy. We derived the quantitative star …
IP Eridani: A surprising long-period binary system hosting a He white dwarf
Jorissen, A.; Masseron, T.; Van Winckel, H. +3 more
We determine the orbital elements for the K0 IV + white dwarf (WD) system IP Eri, which appears to have a surprisingly long period of 1071 d and a significant eccentricity of 0.25. Previous spectroscopic analyses of the WD, based on a distance of 101 pc inferred from its Hipparcos parallax, yielded a mass of only 0.43 M⊙, implying it to…