TY  - JOUR
A1  - Schmidt, Thomas
A1  - Cioni, Maria-Rosa L.
A1  - Niederhofer, Florian
A1  - Bekki, Kenji
A1  - Bell, Cameron P. M.
A1  - de Grijs, Richard
A1  - El Youssoufi, Dalal
A1  - Ivanov, Valentin D.
A1  - Oliveira, Joana M.
A1  - Ripepi, Vincenzo
A1  - van Loon, Jacco Th.
T1  - The VMC survey: XLV. Proper motion of the outer LMC and the impact of the SMC
JF  - Astronomy and astrophysics
N2  - Context. The Large Magellanic Cloud (LMC) is the most luminous satellite galaxy of the Milky Way and, owing to its companion, the Small Magellanic Cloud (SMC), represents an excellent laboratory to study the interaction of dwarf galaxies. Aims. The aim of this study is to investigate the kinematics of the outer regions of the LMC by using stellar proper motions to understand the impact of interactions, for example with the SMC about 250 Myr ago. Methods. We calculate proper motions using multi-epoch K s -band images from the VISTA survey of the Magellanic Cloud system (VMC). Observations span a time baseline of 2-5 yr. We combine the VMC data with data from the Gaia Early Data Release 3 and introduce a new method to distinguish between Magellanic and Milky Way stars based on a machine learning algorithm. This new technique enables a larger and cleaner sample selection of fainter sources as it reaches below the red clump of the LMC. Results. We investigate the impact of the SMC on the rotational field of the LMC and find hints of stripped SMC debris. The southeastern region of the LMC shows a slow rotational speed compared to the overall rotation. N-body simulations suggest that this could be caused by a fraction of stripped SMC stars located in that particular region that move opposite to the expected rotation.
KW  - Galaxy: kinematics and dynamics
KW  - Magellanic Clouds
KW  - galaxies:
KW  - interactions
KW  - proper motions
KW  - surveys
Y1  - 2022
U6  - https://doi.org/10.1051/0004-6361/202142148
SN  - 0004-6361
SN  - 1432-0746
VL  - 663
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Raddi, Roberto
A1  - Hollands, M. A.
A1  - Koester, D.
A1  - Hermes, J. J.
A1  - Gansicke, B. T.
A1  - Heber, Ulrich
A1  - Shen, Ken J.
A1  - Townsley, D. M.
A1  - Pala, Anna Francesca
A1  - Reding, J. S.
A1  - Toloza, O. F.
A1  - Pelisoli, Ingrid Domingos
A1  - Geier, Stephan
A1  - Fusillo, Nicola Pietro Gentile
A1  - Munari, Ullisse
A1  - Strader, J.
T1  - Partly burnt runaway stellar remnants from peculiar thermonuclear supernovae
JF  - Monthly notices of the Royal Astronomical Society
N2  - We report the discovery of three stars that, along with the prototype LP 40-365, form a distinct class of chemically peculiar runaway stars that are the survivors of thermonuclear explosions. Spectroscopy of the four confirmed LP 40-365 stars finds ONe-dominated atmospheres enriched with remarkably similar amounts of nuclear ashes of partial O- and Si-burning. Kinematic evidence is consistent with ejection from a binary supernova progenitor; at least two stars have rest-frame velocities indicating they are unbound to the Galaxy. With masses and radii ranging between 0.20 and 0.28M(circle dot) and between 0.16 and 0.60 R-circle dot, respectively, we speculate these inflated white dwarfs are the partly burnt remnants of either peculiar Type Iax or electron-capture supernovae. Adopting supernova rates from the literature, we estimate that similar to 20 LP 40-365 stars brighter than 19 mag should be detectable within 2 kpc from the Sun at the end of the Gaia mission. We suggest that as they cool, these stars will evolve in their spectroscopic appearance, and eventually become peculiar O-rich white dwarfs. Finally, we stress that the discovery of new LP 40-365 stars will be useful to further constrain their evolution, supplying key boundary conditions to the modelling of explosion mechanisms, supernova rates, and nucleosynthetic yields of peculiar thermonuclear explosions.
KW  - stars: individual: LP 40-365
KW  - subdwarfs
KW  - supernovae: general
KW  - white dwarfs
KW  - Galaxy: kinematics and dynamics
Y1  - 2019
U6  - https://doi.org/10.1093/mnras/stz1618
SN  - 0035-8711
SN  - 1365-2966
VL  - 489
IS  - 2
SP  - 1489
EP  - 1508
PB  - Oxford Univ. Press
CY  - Oxford
ER  -