Search Publications
Low Mass Stars as Tracers of Star and Cluster Formation
Megeath, S. T.; Gutermuth, R. A.; Kounkel, M. A.
We review the use of young low mass stars and protostars, or young stellar objects (YSOs), as tracers of star formation. Observations of molecular clouds at visible, infrared, radio and X-ray wavelengths can identify and characterize the YSOs populating these clouds, with the ability to detect deeply embedded objects at all evolutionary stages. Su…
Orbital Elements and Individual Component Masses from Joint Spectroscopic and Astrometric Data of Double-line Spectroscopic Binaries
Anguita-Aguero, Jennifer; Mendez, Rene A.; Clavería, Rubén M. +1 more
We present orbital elements, orbital parallaxes, and individual component masses for 14 spatially resolved double-line spectroscopic binaries derived doing a simultaneous fit of their visual orbit and radial velocity curve. This was done by means of a Markov Chain Monte Carlo code developed by our group that produces posterior distribution functio…
An Intensity Mapping Constraint on the CO-galaxy Cross-power Spectrum at Redshift 3
Marrone, Daniel P.; Keating, Garrett K.; Keenan, Ryan P.
The abundance of cold molecular gas plays a crucial role in models of galaxy evolution. While deep spectroscopic surveys of CO emission lines have been a primary tool for measuring this abundance, the difficulty of these observations has motivated alternative approaches to studying molecular gas content. One technique, line intensity mapping, seek…
The galaxy-halo size relation of low-mass galaxies in FIRE
Faucher-Giguère, Claude-André; Wetzel, Andrew; Feldmann, Robert +7 more
Galaxy sizes correlate closely with the sizes of their parent dark matter haloes, suggesting a link between halo formation and galaxy growth. However, the precise nature of this relation and its scatter remains to be understood fully, especially for low-mass galaxies. We analyse the galaxy-halo size relation (GHSR) for low-mass ($M_\star \sim 10^{…
Age dissection of the vertical breathing motions in Gaia DR2: evidence for spiral driving
Debattista, Victor P.; Khachaturyants, Tigran; Ghosh, Soumavo
Gaia DR2 has revealed breathing motions in the Milky Way, with stars on both sides of the Galactic mid-plane moving coherently towards or away from it. The generating mechanism of these breathing motions is thought to be spiral density waves. Here, we test this hypothesis. Using a self-consistent, high-resolution simulation with star formation, an…
TESS discovery of a sub-Neptune orbiting a mid-M dwarf TOI-2136
Triaud, Amaury H. M. J.; Latham, David W.; Howell, Steve B. +63 more
We present the discovery of TOI-2136 b, a sub-Neptune planet transiting a nearby M4.5V-type star every 7.85 d, identified through photometric measurements from the Transiting Exoplanet Survey Satellite (TESS) mission. The host star is located 33 pc away with a radius of R* = 0.34 ± 0.02 R⊙, a mass of $0.34\pm 0.02 \, \mathrm{…
Stellar Atmospheric Parameters of M-type Stars from LAMOST DR8
Gao, Qi; Wu, Yue; Yan, Hong-Liang +9 more
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Low Resolution Spectroscopic Survey (LRS) provides massive spectroscopic data on M-type stars, and the derived stellar parameters could bring vital help to various studies. We adopt the ULySS package to perform χ 2 minimization with model spectra generated from the M…
Differential Rotation in Jupiter's Interior Revealed by Simultaneous Inversion for the Magnetic Field and Zonal Flux Velocity
Cao, Hao; Stevenson, David J.; Connerney, John E. P. +5 more
A key objective of the current Juno mission (Bolton et al., 2017, https://doi.org/10.1126/science.aal2108) is the direct determination of the secular variation (time dependency) of Jupiter's internal magnetic field in order to further understand the dynamics of Jupiter's interior. Here, we find…
Across the green valley with HST grisms: colour evolution, crossing time-scales, and the growth of the red sequence at z = 1.0-1.8
Ravindranath, Swara; Willott, Chris J.; Bradač, Maruša +6 more
We measure the colour evolution and quenching time-scales of z = 1.0-1.8 galaxies across the green valley. We derive rest-frame NUVrK colours and select blue-cloud, green-valley, and red-sequence galaxies from the spectral energy distribution modelling of CANDELS GOODS-South and UDS multiband photometry. Separately, we constrain the star-formation…
XMM-Newton observations of the narrow-line Seyfert 1 galaxy IRAS 13224-3809: X-ray spectral analysis II
Fabian, Andrew C.; Reynolds, Christopher S.; Jiang, Jiachen +4 more
Previously, we modelled the X-ray spectra of the narrow-line Seyfert 1 galaxy IRAS 13224-3809 using a disc reflection model with a fixed electron density of 1015 cm-3. An additional blackbody component was required to fit the soft X-ray excess below 2 keV. In this work, we analyse simultaneously five flux-resolved XMM-Newton …