Search Publications
Raman mapping of photodissociation regions
Henney, William J.
Broad Raman-scattered wings of hydrogen lines can be used to map neutral gas illuminated by high-mass stars in star-forming regions. Raman scattering transforms far-ultraviolet starlight from the wings of the Lyβ line (1022-1029 Å) to red visual light in the wings of the Hα line (6400 -6700 Å). Analysis of spatially resolved spectra of the Orion B…
Nigraha: Machine-learning-based pipeline to identify and evaluate planet candidates from TESS
Mahabal, Ashish; Rao, Sriram; Rao, Niyanth +1 more
The Transiting Exoplanet Survey Satellite (TESS) has now been operational for a little over two years, covering the Northern and the Southern hemispheres once. The TESS team processes the downlinked data using the Science Processing Operations Center (SPOC) pipeline and Quick Look pipeline (QLP) to generate alerts for follow-up. Combined with othe…
Searching for multiple populations in Ruprecht 106
Villanova, S.; Fernández-Trincado, J. G.; Muñoz, C. +1 more
More than a decade has passed since the definition of globular cluster (GC) changed, and now we know that they host multiple populations (MPs). But few GCs do not share that behaviour and Ruprecht 106 is one of these clusters. We analysed 13 member red giant branch stars using spectra in the wavelength range 6120-6405 Å obtained through the GIRAFF…
Gaia DR2 giants in the Galactic dust - I. Reddening across the whole dust layer and some properties of the giant clump
Gontcharov, George A.; Mosenkov, Aleksandr V.
We consider a complete sample of 101 810 giants with Gaia Data Realease 2 (DR2) parallaxes ϖ within the red clump domain of the Hertzsprung-Russell diagram in the space cylinder with a radius of 700 pc around the Sun and a height of |Z| = 1800 pc. We use the Gaia DR2 GBP, GRP, and Wide-field Infrared Survey Explorer W3 photom…
The orbital evolution of UFDs and GCs in an evolving Galactic potential
Bekki, Kenji; Armstrong, Benjamin M.; Ludlow, Aaron D.
We use the second Gaia data release to investigate the kinematics of 17 ultra-faint dwarf galaxies (UFDs) and 154 globular clusters (GCs) in the Milky Way, focusing on the differences between static and evolving models of the Galactic potential. An evolving potential modifies a satellite's orbit relative to its static equivalent, though the differ…
Gas clumping in the outskirts of the Virgo cluster
Walker, S. A.; Mirakhor, M. S.
Observations of the intracluster medium (ICM) in the outskirts of the Virgo cluster with Suzaku have found the gas mass fraction in the northern direction to be significantly above the expected level, indicating that there may be a very high level of gas clumping on small scales in this direction. Here we explore the XMM-Newton data in the outskir…
An improved model for the spectra of discs of nova-like variables
Hubeny, Ivan; Long, Knox S.
The spectra arising from the discs of nova-like variables show many of the features seen in stellar atmospheres. They are typically modelled either from an appropriated weighted set of stellar atmospheres or a disc atmosphere with energy is dissipated near the disc plane, with the effective temperature distribution expected from a steady-state acc…
Polarization of hot Jupiter systems: a likely detection of stellar activity and a possible detection of planetary polarization
Bailey, Jeremy; Cotton, Daniel V.; Kedziora-Chudczer, Lucyna +6 more
We present high-precision linear polarization observations of four bright hot Jupiter systems (τ Boo, HD 179949, HD 189733, and 51 Peg) and use the data to search for polarized reflected light from the planets. The data for 51 Peg are consistent with a reflected light polarization signal at about the level expected with 2.8σ significance and a fal…
The clustering of the SDSS-IV extended Baryon Oscillation Spectroscopic Survey quasar sample: testing observational systematics on the Baryon Acoustic Oscillation measurement
Myers, Adam D.; Brownstein, Joel R.; Schneider, Donald P. +15 more
Baryon Acoustic Oscillations (BAO) are considered to be a very robust standard ruler against various systematics. This premise has been tested against observational systematics, but not to the level required for the next generation of galaxy surveys such as the Dark Energy Spectroscopic Instrument (DESI) and Euclid. In this paper, we investigate t…
Age-metallicity dependent stellar kinematics of the Milky Way disc from LAMOST and Gaia
Zhao, Gang; Wu, Yaqian; Xiang, Maosheng +5 more
We investigate the stellar kinematics of the Galactic disc in 7 < R < 13 kpc using a sample of 118 945 red giant branch (RGB) stars from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and Gaia. We characterize the median, dispersion and skewness of the distributions of the three-dimensional stellar velocities, actions…