Search Publications
Spectroscopic evolution of massive stars near the main sequence at low metallicity
Martins, F.; Palacios, A.
Context. The evolution of massive stars is not fully understood. Several physical processes affect their life and death, with major consequences on the progenitors of core-collapse supernovae, long-soft gamma-ray bursts, and compact-object mergers leading to gravitational wave emission.
Aims: In this context, our aim is to make the prediction…
The effect of active galactic nuclei on the cold interstellar medium in distant star-forming galaxies
Daddi, E.; Gómez-Guijarro, C.; Magdis, G. E. +17 more
In the framework of a systematic study with the ALMA interferometer of IR-selected main-sequence and starburst galaxies at z ∼ 1 − 1.7 at typical ∼1″ resolution, we report on the effects of mid-IR- and X-ray-detected active galactic nuclei (AGN) on the reservoirs and excitation of molecular gas in a sample of 55 objects. We find widespread detecta…
Probing the structure of a massive filament: ArTéMiS 350 and 450 µm mapping of the integral-shaped filament in Orion A
Rodriguez, L.; Roussel, H.; André, Ph. +18 more
Context. The Orion molecular cloud is the closest region of high-mass star formation. It is an ideal target for investigating the detailed structure of massive star-forming filaments at high resolution and the relevance of the filament paradigm for the earliest stages of intermediate- to high-mass star formation.
Aims: Within the Orion A mole…
Whistler instability driven by the sunward electron deficit in the solar wind. High-cadence Solar Orbiter observations
Lewis, G. R.; Kataria, D. O.; Livi, S. +19 more
Context. Solar wind electrons play an important role in the energy balance of the solar wind acceleration by carrying energy into interplanetary space in the form of electron heat flux. The heat flux is stored in the complex electron velocity distribution functions (VDFs) shaped by expansion, Coulomb collisions, and field-particle interactions.
A proto-pseudobulge in ESO 320-G030 fed by a massive molecular inflow driven by a nuclear bar
Smith, Howard A.; Colina, Luis; Alonso-Herrero, Almudena +10 more
Galaxies with nuclear bars are believed to efficiently drive gas inward, generating a nuclear starburst and possibly an active galactic nucleus. We confirm this scenario for the isolated, double-barred, luminous infrared galaxy ESO 320-G030 based on an analysis of Herschel and ALMA spectroscopic observations. Herschel/PACS and SPIRE observations o…
Exploring HNC and HCN line emission as probes of the protoplanetary disk temperature
Bosman, Arthur D.; Guzmán, Viviana V.; Long, Feng +6 more
Context. The distributions and abundances of molecules in protoplanetary disks are powerful tracers of the physical and chemical disk structures. The abundance ratios of HCN and its isomer HNC are known to be sensitive to gas temperature. Their line ratios might therefore offer a unique opportunity to probe the properties of the emitting gas.
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Probing protoplanetary disk evolution in the Chamaeleon II region
Pinte, C.; Ménard, F.; Dent, W. R. F. +13 more
Context. Characterizing the evolution of protoplanetary disks is necessary to improve our understanding of planet formation. Constraints on both dust and gas are needed to determine the dominant disk dissipation mechanisms.
Aims: We aim to compare the disk dust masses in the Chamaeleon II (Cha II) star-forming region with other regions with a…
Radial evolution of the April 2020 stealth coronal mass ejection between 0.8 and 1 AU. Comparison of Forbush decreases at Solar Orbiter and near the Earth
Dumbović, Mateja; Möstl, Christian; Davies, Emma E. +40 more
Aims: We present observations of the first coronal mass ejection (CME) observed by the Solar Orbiter spacecraft on April 19, 2020 and the associated Forbush decrease (FD) measured by the High Energy Telescope (HET). This CME is a multi-spacecraft event that was also seen near Earth the following day.
Methods: We highlight the capabilitie…
A2A: 21 000 bulge stars from the ARGOS survey with stellar parameters on the APOGEE scale
Freeman, K. C.; Bland-Hawthorn, J.; Ness, M. K. +3 more
Aims: Spectroscopic surveys have by now collectively observed tens of thousands of stars in the bulge of our Galaxy. However, each of these surveys had unique observing and data processing strategies that led to distinct stellar parameter and abundance scales. Because of this, stellar samples from different surveys cannot be directly combined…
Transient obscuration event captured in NGC 3227. I. Continuum model for the broadband spectral energy distribution
Kaastra, J. S.; Kriss, G. A.; Arav, N. +21 more
From Swift monitoring of a sample of active galactic nuclei (AGN) we found a transient X-ray obscuration event in Seyfert-1 galaxy NGC 3227, and thus triggered our joint XMM-Newton, NuSTAR, and Hubble Space Telescope (HST) observations to study this event. Here in the first paper of our series we present the broadband continuum modelling of the sp…