Search Publications
Dynamical Stellar Masses of Pre-main-sequence Stars in Lupus and Taurus Obtained with ALMA Surveys in Comparison with Stellar Evolutionary Models
Koch, Patrick M.; Yen, Hsi-Wei; Testi, Leonardo +3 more
We analyzed archival molecular line data of pre-main-sequence (PMS) stars in the Lupus and Taurus star-forming regions obtained with ALMA surveys with an integration time of a few minutes per source. We stacked the data of 13CO and C18O (J = 2-1 and 3-2) and CN (N = 3-2, J = 7/2-5/2) lines to enhance the signal-to-noise ratio…
A Multi-Purpose Heliophysics L4 Mission
Solanki, S. K.; Arge, C. N.; Henney, C. J. +13 more
The Earth-Sun Lagrangian point 4 is a meta-stable location at 1 AU from the Sun, 60° ahead of Earth's orbit. It has an uninterrupted view of the solar photosphere centered on W60, the Earth's nominal magnetic field connection to the Sun. Such a mission on its own would serve as a solar remote sensing observatory that would oversee the entire solar…
M17 MIR: A Massive Protostar with Multiple Accretion Outbursts
Chen, Zhiwei; Chen, Xuepeng; Haas, Martin +3 more
We report the discovery of a massive protostar M17 MIR embedded in a hot molecular core in M17. The multiwavelength data obtained during 1993-2019 show significant mid-IR (MIR) variations, which can be split into three stages: the decreasing phase during 1993.03-mid-2004, the quiescent phase from mid-2004 to mid-2010, and the rebrightening phase f…
Red noise and pulsations in evolved massive stars
Nazé, Yaël; Gosset, Eric; Rauw, Gregor
We examine high-cadence space photometry taken by the Transiting Exoplanet Survey Satellite (TESS) of a sample of evolved massive stars: 26 Wolf-Rayet stars (WRs) and eight luminous blue variables (LBVs) or candidate LBVs. To avoid confusion problems, only stars without bright Gaia neighbours and without evidence of bound companions are considered…
A high-rate foreground of sub-second flares from geosynchronous satellites
Ofek, Eran O.; Polishook, David; Nir, Guy +3 more
The Weizmann Fast Astronomical Survey Telescope is a 55 cm optical survey telescope with a high-cadence (25 Hz) monitoring of the sky over a wide field of view (≈7 deg2). The high frame rate allows detection of sub-second transients over multiple images. We present a sample of ~0.1-0.3 s duration flares detected in an untargeted survey …
A bottom-heavy initial mass function for the likely-accreted blue-halo stars of the Milky Way
Maoz, Dan; Hallakoun, Na'ama
We use Gaia DR2 to measure the initial mass function (IMF) of stars within 250 pc and masses in the range of 0.2 < m/M⊙ < 1.0, separated according to kinematics and metallicity, as determined from Gaia transverse velocity, vT, and location on the Hertzsprung-Russell diagram (HRD). The predominant thin-disc population (v…
Studying the ISM at ∼10 pc scale in NGC 7793 with MUSE. II. Constraints on the oxygen abundance and ionising radiation escape
Della Bruna, Lorenza; Östlin, Göran; Smith, Linda J. +11 more
Context. Feedback from massive stars affects the interstellar medium (ISM) from the immediate surroundings of the stars (parsec scales) to galactic (kiloparsec) scales. High-spatial resolution studies of H II regions are critical to investigate how this mechanism operates.
Aims: We study the ionised ISM in NGC 7793 with the MUSE instrument at…
Millimeter-sized Dust Grains Surviving the Water-sublimating Temperature in the Inner 10 au of the FU Ori Disk
Chen, Wen Ping; Liu, Sheng-Yuan; Takami, Michihiro +11 more
Previous observations have shown that the ≲10 au, ≳400 K hot inner disk of the archetypal accretion outburst young stellar object, FU Ori, is dominated by viscous heating. To constrain dust properties in this region, we have performed radio observations toward this disk using the Karl G. Jansky Very Large Array in 2020 June-July, September, and No…
SCExAO/MEC and CHARIS Discovery of a Low-mass, 6 au Separation Companion to HIP 109427 Using Stochastic Speckle Discrimination and High-contrast Spectroscopy
Currie, Thayne; Tamura, Motohide; Bailey, John I., III +29 more
We report the direct imaging discovery of a low-mass companion to the nearby accelerating A star, HIP 109427, with the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument coupled with the Microwave Kinetic Inductance Detector Exoplanet Camera (MEC) and CHARIS integral field spectrograph. CHARIS data reduced with reference star point s…
High-resolution synthetic UV-submm images for simulated Milky Way-type galaxies from the Auriga project
van der Wel, Arjen; De Looze, Ilse; Baes, Maarten +6 more
We present redshift-zero synthetic observational data considering dust attenuation and dust emission for the 30 galaxies of the Auriga project, calculated with the SKIRT radiative transfer code. The post-processing procedure includes components for star-forming regions, stellar sources, and diffuse dust taking into account stochastic heating of du…