Search Publications
30-micron sources in galaxies with different metallicities
Szczerba, R.; Lagadec, E.; Volk, K. +2 more
Aims: We present an analysis and comparison of the 30 µm dust features seen in the Spitzer Space Telescope spectra of 207 carbon-rich asymptotic giant branch (AGB) stars, post-AGB objects, and planetary nebulae (PNe) located in the Milky Way, the Magellanic Clouds (MCs), or the Sagittarius dwarf spheroidal galaxy (Sgr dSph), which are c…
HR 10: a main-sequence binary with circumstellar envelopes around both components. Discovery and analysis
Eiroa, C.; Montesinos, B.; Absil, O. +16 more
Context. This paper is framed within a large project devoted to studying the presence of circumstellar material around main sequence stars, and looking for exocometary events. The work concentrates on HR 10 (A2 IV/V), known for its conspicuous variability in the circumstellar narrow absorption features of Ca II K and other lines, so far interprete…
IGR J17503-2636: a candidate supergiant fast X-ray transient
Sanna, A.; Ferrigno, C.; Di Salvo, T. +4 more
The object IGR J17503-2636 is a hard X-ray transient discovered by INTEGRAL on 2018 August 11. This was the first ever reported X-ray emission from this source. Following the discovery, follow-up observations were carried out with Swift, Chandra, NICER, and NuSTAR. Here we report on the analysis of all of these X-ray data and the results obtained.…
Deuterated methanol toward NGC 7538-IRS1
Fedele, D.; Favre, C.; Lefloch, B. +7 more
We investigate the deuteration of methanol towards the high-mass star-forming region NGC 7538-IRS1. We carried out a multi-transition study of CH3OH, 13CH3OH, and the deuterated flavors, CH2DOH and CH3OD, between 1.0 and 1.4 mm with the IRAM-30 m antenna. In total, 34 13CH3
Detection of Hα emission from PZ Telescopii B using SPHERE/ZIMPOL
Henning, Thomas; Musso Barcucci, Arianna; Launhardt, Ralf +6 more
Hα is a powerful tracer of accretion and chromospheric activity, which has been detected in the case of young brown dwarfs and even recently in planetary mass companions (e.g. PDS70 b and c). Hα detections and characterisation of brown dwarf and planet companions can further our knowledge of their formation and evolution, and expanding such a samp…
Kinematics and dynamics of the luminous infrared galaxy pair NGC 5257/58 (Arp 240)
Rosado, M.; Amram, P.; Fuentes-Carrera, I. +6 more
Context. Encounters between galaxies modify their morphology, kinematics, and star formation history. The relation between these changes and external perturbations is not straightforward. The great number of parameters involved requires both the study of large samples and individual encounters where particular features, motions, and perturbations …
Radio observations of evaporating objects in the Cygnus OB2 region
del Palacio, S.; Fernández-López, M.; Ishwara-Chandra, C. H. +2 more
We present observations of the Cygnus OB2 region obtained with the Giant Metrewave Radio Telescope (GMRT) at frequencies of 325 and 610 MHz. In this contribution we focus on the study of proplyd-like objects (also known as free-floating evaporating gas globules or frEGGs) that typically show an extended cometary morphology. We identify eight objec…
Strongly magnetic Ap stars in the Gaia DR2 Hertzsprung-Russell diagram . I. Selecting the most reliable astrometric and photometric data
Hubrig, S.; Chojnowski, S. Drew; Scholz, R. -D.
Context. Knowing the distribution of strongly magnetic Ap stars in the Hertzsprung-Russell diagram (HRD) allows us to study the evolution of their magnetic fields across the main sequence (MS). With a newly extended Ap star sample from APOGEE and available Gaia DR2 data, we can now critically review the results of previous studies based on HIPPARC…
Distance to the nearby dwarf galaxy [TT2009] 25 in the NGC 891 group using the tip of the red giant branch
Müller, Oliver; Ibata, Rodrigo; Rejkuba, Marina +1 more
Dwarf galaxies are key objects for small-scale cosmological tests like the abundance problems or the planes-of-satellites problem. A crucial task is therefore to get accurate information for as many nearby dwarf galaxies as possible. Using extremely deep, ground-based V and i-band Subaru Suprime Cam photometry with a completeness of i = 27 mag, we…
CSI 2264: Simultaneous optical and X-ray variability in the pre-main sequence stars of NGC 2264. II. Photometric variability, magnetic activity, and rotation in class III objects and stars with transition disks
Micela, G.; Stauffer, J.; Sciortino, S. +6 more
Context. Pre-main sequence stars are variable sources. In diskless stars this variability is mainly due to the rotational modulation of dark photospheric spots and active regions, as in main sequence stars even if associated with a stronger magnetic activity.
Aims: We aim at analyzing the simultaneous optical and X-ray variability in these st…