Search Publications
Extended stellar systems in the solar neighborhood. IV. Meingast 1: the most massive stellar stream in the solar neighborhood
Meingast, Stefan; Alves, João; Ratzenböck, Sebastian +2 more
Context. Nearby stellar streams carry unique information on the dynamical evolution and disruption of stellar systems in the Galaxy, the mass distribution in the disk, and they provide unique targets for planet formation and evolution studies. Recently, Meingast 1, a 120° stellar stream with a length of at least 400 pc, was dicovered.
Aims: W…
Probing the origin of low-frequency radio emission in PG quasars with the uGMRT - I
Ho, L. C.; Ishwara-Chandra, C. H.; Harrison, C. +3 more
We present the results from 685 MHz observations with the upgraded Giant Metrewave Radio Telescope (uGMRT) of 22 quasars belonging to the Palomar-Green (PG) quasar sample. Only four sources reveal extended radio structures on ∼10-30 kpc scales, while the rest are largely a combination of a radio core unresolved at the uGMRT resolution of ∼3-5 arcs…
An extended Pal 5 stream in Gaia DR2
Bovy, Jo; Webb, Jeremy J.; Starkman, Nathaniel
We present the results of a detailed search for members of the Pal 5 tidal tail system in Gaia Data Release 2 (DR2). Tidal tails provide a sensitive method for measuring the current and past gravitational potential of their host galaxy as well as for testing predictions for the abundance of dark matter subhaloes. The Pal 5 globular cluster and its…
Distribution of star formation in galactic bars as seen with Hα and stacked GALEX UV imaging
Knapen, J. H.; Comerón, S.; Salo, H. +3 more
Context. Stellar bars are known to gradually funnel gas to the central parts of disk galaxies. It remains a matter of debate why the distribution of ionized gas along bars and in the circumnuclear regions varies among galaxies.
Aims: Our goal is to investigate the spatial distribution of star formation (SF) within bars of nearby low-inclinati…
Martian Water Ice Clouds During the 2018 Global Dust Storm as Observed by the ACS-MIR Channel Onboard the Trace Gas Orbiter
Montmessin, F.; Fedorova, A.; Korablev, O. +8 more
The Atmospheric Chemistry Suite (ACS) instrument onboard the ExoMars Trace Gas Orbiter (TGO) European Space Agency-Roscosmos mission began science operations in March 2018. ACS Mid-InfraRed (MIR) channel notably provides solar occultation observations of the Martian atmosphere in the 2.3- to 4.2-µ m spectral range. Here, we use these observa…
Fine Structure of a Solar Type II Radio Burst Observed by LOFAR
Zucca, Pietro; Vocks, Christian; Mann, Gottfried +6 more
Shock waves in the solar corona are closely associated with coronal mass ejections and flares. The longest-known and frequently studied signatures of coronal shock waves are metric type II radio bursts, which provide information on the shock driver and ambient plasma conditions. We report on outstanding high frequency/time resolution LOw Frequency…
3D chemical structure of diffuse turbulent ISM. I. Statistics of the HI-to-H2 transition
Godard, B.; Pérault, M.; Hennebelle, P. +4 more
Context. The amount of data collected by spectrometers from radio to ultraviolet (UV) wavelengths opens a new era where the statistical and chemical information contained in the observations can be used concomitantly to investigate the thermodynamical state and the evolution of the interstellar medium (ISM).
Aims: In this paper, we study the …
Trimodal structure of Hercules stream explained by originating from bar resonances
Portegies Zwart, S.; Asano, Tetsuro; Fujii, M. S. +3 more
Gaia Data Release 2 revealed detailed structures of nearby stars in phase space. These include the Hercules stream, whose origin is still debated. Most of the previous numerical studies conjectured that the observed structures originate from orbits in resonance with the bar, based on static potential models for the Milky Way. We, in contrast, appr…
A Suzaku sample of unabsorbed narrow-line and broad-line Seyfert 1 galaxies - I. X-ray spectral properties
Gallo, L. C.; Waddell, S. G. H.
A sample of narrow-line Seyfert 1 (NLS1) and broad-line Seyfert 1 (BLS1) galaxies observed with Suzaku is presented. The final sample consists of 22 NLS1s and 47 BLS1s, for a total of 69 active galactic nuclei (AGNs) that are all at low redshift (z < 0.5) and exhibit low host-galaxy column densities (<1022 ${\rm cm}^{-2}\,$ ). The…
HST/STIS transmission spectrum of the ultra-hot Jupiter WASP-76 b confirms the presence of sodium in its atmosphere
Mallonn, M.; Kjeldsen, H.; von Essen, C. +4 more
We present an atmospheric transmission spectrum of the ultra-hot Jupiter WASP-76 b by analyzing archival data obtained with the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope (HST). The dataset spans three transits, two with a wavelength coverage between 2900 and 5700 Å, and the third one between 5250 and 10 300 Å.…