Search Publications
A Low-mass Stellar-debris Stream Associated with a Globular Cluster Pair in the Halo
Huang, Yang; Beers, Timothy C.; Chang, Jiang +1 more
There are expected to be physical relationships between the globular clusters (GCs) and stellar substructures in the Milky Way, not all of which have yet been found. We search for such substructures from a combined halo sample of SDSS blue horizontal-branch and SDSS+LAMOST RR Lyrae stars, cross-matched with astrometric information from Gaia DR2. T…
Modelling the He I triplet absorption at 10 830 Å in the atmosphere of HD 209458 b
Alonso-Floriano, F. J.; Sánchez-López, A.; López-Puertas, M. +16 more
Context. HD 209458 b is an exoplanet with an upper atmosphere undergoing blow-off escape that has mainly been studied using measurements of the Lyα absorption. Recently, high-resolution measurements of absorption in the He I triplet line at 10 830 Å of several exoplanets (including HD 209458 b) have been reported, creating a new opportunity to pro…
Palomar Gattini-IR: Survey Overview, Data Processing System, On-sky Performance and First Results
Soria, Roberto; Burdge, Kevin B.; De, Kishalay +24 more
Palomar Gattini-IR is a new wide-field, near-infrared (NIR) robotic time domain survey operating at Palomar Observatory. Using a 30 cm telescope mounted with a H2RG detector, Gattini-IR achieves a field of view (FOV) of 25 sq. deg. with a pixel scale of 8.″7 in J-band. Here, we describe the system design, survey operations, data processing system …
A Probabilistic Approach to Kepler Completeness and Reliability for Exoplanet Occurrence Rates
Huber, D.; Mullally, S. E.; Berger, T. +5 more
Exoplanet catalogs produced by surveys suffer from a lack of completeness (not every planet is detected) and less than perfect reliability (not every planet in the catalog is a true planet), particularly near the survey's detection limit. Exoplanet occurrence rate studies based on such a catalog must be corrected for completeness and reliability. …
X-ray detected AGN in SDSS dwarf galaxies
Birchall, Keir L.; Watson, M. G.; Aird, J.
In this work we present a robust quantification of X-ray selected AGN in local (z ≤ 0.25) dwarf galaxies (M_* ≤ 3 × 10^9 M_⊙ ). We define a parent sample of 4331 dwarf galaxies found within the footprint of both the MPA-JHU galaxy catalogue (based on SDSS DR8) and 3XMM DR7, performed a careful review of the data to remove misidentifications and pr…
Stellar rotation periods from K2 Campaigns 0-18. Evidence for rotation period bimodality and simultaneous variability decrease
Reinhold, Timo; Hekker, Saskia
Context. Rotation period measurements of stars observed with the Kepler mission have revealed a lack of stars at intermediate rotation periods, accompanied by a decrease of photometric variability. Whether this so-called dearth region is a peculiarity of stars in the Kepler field, or reflects a general manifestation of stellar magnetic activity, i…
The Southern Stellar Stream Spectroscopic Survey (S5): Chemical Abundances of Seven Stellar Streams
Lewis, Geraint F.; Casey, Andrew R.; Hattori, Kohei +16 more
We present high-resolution Magellan/MIKE spectroscopy of 42 red giant stars in seven stellar streams confirmed by the Southern Stellar Stream Spectroscopic Survey (S5): ATLAS, Aliqa Uma, Chenab, Elqui, Indus, Jhelum, and Phoenix. Abundances of 30 elements have been derived from over 10,000 individual line measurements or upper limits us…
Non-detection of TiO and VO in the atmosphere of WASP-121b using high-resolution spectroscopy
Hooton, M. J.; Gibson, N. P.; Sing, D. K. +9 more
Thermal inversions have long been predicted to exist in the atmospheres of ultra-hot Jupiters. However, the detection of two species thought to be responsible - titanium oxide and vanadium oxide - remains elusive. We present a search for TiO and VO in the atmosphere of the ultra-hot Jupiter WASP-121b (Teq ≳ 2400 K), an exoplanet with ev…
HOLISMOKES. II. Identifying galaxy-scale strong gravitational lenses in Pan-STARRS using convolutional neural networks
Suyu, S. H.; Lemon, C.; Cañameras, R. +6 more
We present a systematic search for wide-separation (with Einstein radius θE ≳ 1.5″), galaxy-scale strong lenses in the 30 000 deg2 of the Pan-STARRS 3π survey on the Northern sky. With long time delays of a few days to weeks, these types of systems are particularly well-suited for catching strongly lensed supernovae with spat…
The R136 star cluster dissected with Hubble Space Telescope/STIS - II. Physical properties of the most massive stars in R136
Vink, Jorick S.; Brands, Sarah A.; Langer, Norbert +11 more
We present an optical analysis of 55 members of R136, the central cluster in the Tarantula Nebula of the Large Magellanic Cloud. Our sample was observed with STIS aboard the Hubble Space Telescope, is complete down to about 40 M⊙, and includes seven very massive stars with masses over 100 M⊙. We performed a spectroscopic anal…