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OB stars and YSO populations in the region of NGC 6334-NGC 6357 as seen with Gaia DR2
Adami, C.; Zavagno, A.; Russeil, D. +3 more
Aims: Our goal is to better understand the origin and the star-formation history of regions NGC 6334 and NGC 6357. We focus our study on the kinematics of young stars (young stellar objects and OB stars) in both regions mainly on the basis of the Gaia DR2 data.
Methods: For both regions, we compiled catalogs of OB stars and young stellar…
Probing Axial Symmetry Breaking in the Galaxy with Gaia Data Release 2
Yanny, Brian; Gardner, Susan; Hinkel, Austin
We study a set of solar neighborhood (d < 3 kpc) stars from Gaia Data Release 2 to determine azimuthal star count differences, I.e., left and right of the line from the Galactic Center (GC) through the Sun - and compare these differences north and south. In this companion paper to Gardner et al., we delineate our procedures to remove false asym…
Suzaku Measurements of Hot Halo Emission at Outskirts for Two Poor Galaxy Groups: NGC 3402 and NGC 5129
Sun, Ming; Dai, Xinyu; Nugent, Jenna M.
We present Suzaku off-center observations of two poor galaxy groups, NGC 3402 and NGC 5129, with temperatures below 1 keV. Through spectral decomposition, we measured their surface brightnesses and temperatures out to 530 and 1430 times the critical density of the universe for NGC 3402 and NGC 5129, respectively. These quantities are consistent wi…
Large-scale changes of the cloud coverage in the ɛ Indi Ba and Bb system
Henning, T.; Lowry, S.; Snodgrass, C. +23 more
We present the results of 14 nights of I-band photometric monitoring of the nearby brown dwarf binary, ɛ Indi Ba and Bb. Observations were acquired over 2 months, with a total of close to 42 h of coverage at a typically high cadence of 1.4 min. At a separation of just 0.7 arcsec, we do not resolve the individual components, and so effectively trea…
Multiwavelength modelling of the circumstellar environment of the massive protostar AFGL 2591 VLA 3
Motte, F.; Beuther, H.; Kuiper, R. +13 more
We have studied the dust density, temperature, and velocity distributions of the archetypal massive young stellar object (MYSO) AFGL 2591. Given its high luminosity ( $L=2\times 10^5\, \mbox{L$_{\odot}$}$ ) and distance (d = 3.3 kpc), AFGL 2591 has one of the highest $\sqrt{L}/d$ ratio, giving better resolved dust emission than any other MYSO. As …
The Capon method for Mercury's magnetic field analysis
Motschmann, Uwe; Toepfer, Simon; Narita, Yasuhito +1 more
Characterization of Mercury's internal and external magnetic field is one of the primary goals of the magnetometer experiment on board the BepiColombo MPO (Mercury Planetary Orbiter) spacecraft. A novel data analysis tool is developed to determine the Gauss coefficients in the multipole expansion using Capon's minimum variance projection method. T…
Setting the scene for BUFFALO: a study of the matter distribution in the HFF galaxy cluster MACS J0416.1-2403 and its parallel field
Diego, J. M.; Steinhardt, C. L.; Koekemoer, A. M. +11 more
In the context of the Beyond Ultradeep Frontier Fields And Legacy Observations (BUFFALO) survey, we present a new analysis of the merging galaxy cluster MACS J0416.1-2403 (z = 0.397) and its parallel field using Hubble Frontier Fields (HFF) data. We measure the surface mass density from a weak-lensing analysis and characterize the overall matter d…
Bipolar molecular outflow of the very low-mass star Par-Lup3-4. Evidence for scaled-down low-mass star formation
de Gregorio-Monsalvo, I.; Huélamo, N.; Testi, L. +7 more
Context. Very low-mass stars are known to have jets and outflows, which is indicative of a scaled-down version of low-mass star formation. However, only very few outflows in very low-mass sources are well characterized.
Aims: We characterize the bipolar molecular outflow of the very low-mass star Par-Lup3-4, a 0.12 M⊙ object known …
BRITE photometry and STELLA spectroscopy of bright stars in Auriga: Rotation, pulsation, orbits, and eclipses⋆
Strassmeier, K. G.; Weber, M.; Granzer, T. +7 more
Context. Knowing rotational and pulsational periods across the Hertzsprung-Russell diagram is of top priority for understanding stellar activity as a function of time.
Aims: We aim to determine periods for bright stars in the Auriga field that are otherwise not easily accessible for ground-based photometry.
Methods: Continuous photometry…
Fluid Theory of Coherent Magnetic Vortices in High-β Space Plasmas
Alexandrova, Olga; Maksimović, Milan; Jovanović, Dušan +1 more
In situ observations in Earth's and Saturn's magnetosheaths and in the solar wind reveal the presence of Alfvén vortices as intermittent structures in the range of scales from fluid lengths down to a few ion lengths. The density and the magnetic field associated with them appear to be compressible for higher plasma betas. Until now, only incompres…