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Potential vorticity structure of Titan's polar vortices from Cassini CIRS observations
DOI: 10.1016/j.icarus.2020.114030 Bibcode: 2021Icar..35414030S

Nixon, Conor A.; Irwin, Patrick G. J.; Teanby, Nicholas A. +4 more

The Cassini mission has provided the best opportunity to date to extensively study the seasonal variation in Titan's atmosphere, with observations spanning almost half a Titan year (Ls = 293 - 93 °). An important feature in the Titan middle-atmosphere is the formation of a polar vortex. Observations have shown that an initially well-dev…

2021 Icarus
Cassini 18
The outer disc in shambles: Blind detection of Monoceros and the ACS with Gaia's astrometric sample
DOI: 10.1051/0004-6361/202039830 Bibcode: 2021A&A...646A..99R

Anders, F.; Antoja, T.; Ramos, P. +5 more

Context. The Gaia astrometric sample allows us to study the outermost Galactic disc, the halo, and their interface. It is precisely at the very edge of the disc where the effects of external perturbations are expected to be the most noticeable.
Aims: Our goal is to detect the kinematic substructure present in the halo and at the edge of the M…

2021 Astronomy and Astrophysics
Gaia 18
Identification of Sagittarius stream members in angular momentum space with gaussian mixture techniques
DOI: 10.1093/mnrasl/slab090 Bibcode: 2021MNRAS.508L..26P

Peñarrubia, Jorge; Petersen, Michael S.

This paper uses Gaussian mixture techniques to dissect the Milky Way (MW) stellar halo in angular momentum space. Application to a catalogue of 5389 stars near the plane of the Sagittarius (Sgr) stream with full 6D phase-space coordinates supplied by Gaia EDR3 and SEGUE returns four independent dynamical components. The broadest and most populated…

2021 Monthly Notices of the Royal Astronomical Society
Gaia 18
Confirmation of two new Galactic bulge globular clusters: FSR 19 and FSR 25
DOI: 10.1051/0004-6361/202141332 Bibcode: 2021A&A...654A..39O

Minniti, D.; Alonso-García, J.; Gómez, M. +1 more

Context. Globular clusters (GCs) in the Milky Way (MW) bulge are very difficult to study for the following reasons: (i) they suffer from the severe crowding and Galactic extinction, which are characteristic of these inner Galactic regions; (ii) they are more prone to the effects of dynamical processes. Therefore, they are relatively faint and diff…

2021 Astronomy and Astrophysics
Gaia 18
The nearby extreme accretion and feedback system PDS 456: finding a complex radio-emitting nucleus
DOI: 10.1093/mnras/staa2445 Bibcode: 2021MNRAS.500.2620Y

Nardini, Emanuele; Paragi, Zsolt; Varenius, Eskil +5 more

When a black hole accretes close to the Eddington limit, the astrophysical jet is often accompanied by radiatively driven, wide-aperture and mildly relativistic winds. Powerful winds can produce significant non-thermal radio emission via shocks. Among the nearby critical accretion quasars, PDS 456 has a very massive black hole (about 1 billion sol…

2021 Monthly Notices of the Royal Astronomical Society
Gaia Herschel ISO 18
Atomic Transition Probabilities of Neutral Calcium
DOI: 10.3847/1538-4365/ac04b1 Bibcode: 2021ApJS..255...27D

Sneden, C.; Sobeck, J.; Roederer, I. U. +3 more

The goals of this study are (1) to test the best theoretical transition probabilities for Ca I (a relatively light alkaline earth spectrum) from a modern ab initio calculation using configuration interaction plus many-body perturbation theory against the best modern experimental transition probabilities and (2) to produce as accurate and comprehen…

2021 The Astrophysical Journal Supplement Series
eHST 18
The Post-impact Evolution of the X-Ray-emitting Gas in SNR 1987A as Viewed by XMM-Newton
DOI: 10.3847/1538-4357/ac033d Bibcode: 2021ApJ...916...41S

Vink, Jacco; Zhou, Ping; Pühlhofer, Gerd +4 more

Since 1996 the blast wave driven by SN 1987A has been interacting with the dense circumstellar material, which provides us with a unique opportunity to study the early evolution of a newborn supernova remnant (SNR). Based on the XMM-Newton RGS and EPIC-pn X-ray observations from 2007 to 2019, we investigated the post-impact evolution of the X-ray-…

2021 The Astrophysical Journal
XMM-Newton 18
Mars moon ephemerides after 14 years of Mars Express data
DOI: 10.1051/0004-6361/202039406 Bibcode: 2021A&A...650A..64L

Jaumann, R.; Oberst, J.; Rosenblatt, P. +7 more

The Mars Express (MEX) mission has been successfully operated around Mars since 2004. Among many results, MEX has provided some of the most accurate astrometric data of the two Mars moons, Phobos and Deimos. We present new ephemerides of the Mars moons benefitting from all previously published astrometric data to the most recent MEX SRC data. Obse…

2021 Astronomy and Astrophysics
MEx 18
The size and pervasiveness of Ly α-UV spatial offsets in star-forming galaxies at z ∼ 6
DOI: 10.1093/mnras/stab924 Bibcode: 2021MNRAS.504.3662L

Ryan, R. E.; Alvarez, C.; Hoag, A. +21 more

We study the projected spatial offset between the ultraviolet continuum and Ly α emission for 65 lensed and unlensed galaxies in the Epoch of Reionization (5 ≤ z ≤ 7), the first such study at these redshifts, in order to understand the potential for these offsets to confuse estimates of the Ly α properties of galaxies observed in slit spectroscopy…

2021 Monthly Notices of the Royal Astronomical Society
eHST 18
Classifying the Magnetosheath Behind the Quasi-Parallel and Quasi-Perpendicular Bow Shock by Local Measurements
DOI: 10.1029/2021JA029269 Bibcode: 2021JGRA..12629269K

Nilsson, H.; Karlsson, T.; Raptis, S. +1 more

We investigate and evaluate the possibility of using local magnetosheath measurements to classify the plasma according to upstream conditions. In order to do this, we use simultaneous measurements from the Cluster spacecraft from time intervals when one of them is located in the solar wind, and the other in the magnetosheath. In particular, we stu…

2021 Journal of Geophysical Research (Space Physics)
Cluster 18