Search Publications
MMT/MMIRS spectroscopy of z = 1.3 - 2.4 extreme [O III] emitters: implications for galaxies in the reionization era
Charlot, Stéphane; Chevallard, Jacopo; Tang, Mengtao +1 more
Galaxies in the reionization era have been shown to have prominent [O III] + H β emission. Little is known about the gas conditions and radiation field of this population, making it challenging to interpret the spectra emerging at z ≳ 6. Motivated by this shortcoming, we have initiated a large MMT spectroscopic survey identifying rest-frame optica…
Gaia-derived luminosities of Kepler A/F stars and the pulsator fraction across the δ Scuti instability strip
Bedding, Timothy R.; Murphy, Simon J.; Van Reeth, Timothy +1 more
We study the fraction of stars in and around the δ Scuti instability strip that are pulsating, using Gaia DR2 parallaxes to derive precise luminosities. We classify a sample of over 15 000 Kepler A and F stars into δ Sct and non-δ Sct stars, paying close attention to variability that could have other origins. We find that 18 per cent of the δ Sct …
The mass of the Milky Way from satellite dynamics
Grand, Robert J. J.; Gómez, Facundo A.; Marinacci, Federico +6 more
We present and apply a method to infer the mass of the Milky Way (MW) by comparing the dynamics of MW satellites to those of model satellites in the EAGLE cosmological hydrodynamics simulations. A distribution function (DF) for galactic satellites is constructed from EAGLE using specific angular momentum and specific energy, which are scaled so as…
Elemental and molecular abundances in comet 67P/Churyumov-Gerasimenko
Mall, Urs; De Keyser, Johan; Hansen, Kenneth C. +18 more
Comets are considered to be some of the most pristine and unprocessed Solar system objects accessible to in situ exploration. Investigating their molecular and elemental composition takes us on a journey back to the early period of our Solar system and possibly even further. In this work, we deduce the bulk abundances of the major volatile species…
The ASAS-SN catalogue of variable stars III: variables in the southern TESS continuous viewing zone
Kochanek, C. S.; Stanek, K. Z.; Dong, Subo +13 more
The All-Sky Automated Survey for Supernovae (ASAS-SN) provides long-baseline (∼4 yr) light curves for sources brighter than V ≲ 17 mag across the whole sky. The Transiting Exoplanet Survey Satellite (TESS) has started to produce high-quality light curves with a baseline of at least 27 d, eventually for most of the sky. The combination of ASAS-SN a…
Simultaneous calibration of spectro-photometric distances and the Gaia DR2 parallax zero-point offset with deep learning
Bovy, Jo; Leung, Henry W.
Gaia measures the five astrometric parameters for stars in the Milky Way, but only four of them (positions and proper motion, but not distance) are well measured beyond a few kpc from the Sun. Modern spectroscopic surveys such as APOGEE cover a large area of the Milky Way disc and we can use the relation between spectra and luminosity to determine…
The afterglow and kilonova of the short GRB 160821B
Troja, E.; Cenko, S. B.; Sakamoto, T. +24 more
GRB 160821B is a short duration gamma-ray burst (GRB) detected and localized by the Neil Gehrels Swift Observatory in the outskirts of a spiral galaxy at z = 0.1613, at a projected physical offset of 16 kpc from the galaxy's center. We present X-ray, optical/nIR, and radio observations of its counterpart and model them with two distinct components…
A long-lived neutron star merger remnant in GW170817: constraints and clues from X-ray observations
Troja, E.; Piro, L.; van Eerten, H. +12 more
Multimessenger observations of GW170817 have not conclusively established whether the merger remnant is a black hole (BH) or a neutron star (NS). We show that a long-lived magnetized NS with a poloidal field B ≈ 1012 G is fully consistent with the electromagnetic dataset, when spin-down losses are dominated by gravitational wave (GW) em…
Characterizing circumgalactic gas around massive ellipticals at z ∼ 0.4 - II. Physical properties and elemental abundances
Weiner, Benjamin J.; Johnson, Sean D.; Zahedy, Fakhri S. +5 more
We present a systematic investigation of the circumgalactic medium (CGM) within projected distances d < 160 kpc of luminous red galaxies (LRGs). The sample comprises 16 intermediate-redshift (z = 0.21-0.55) LRGs of stellar mass M_star> 10^{11} M_\odot. Combining far-ultraviolet Cosmic Origin Spectrograph spectra from the Hubble Space Telesco…
Three-dimensional interstellar dust reddening maps of the Galactic plane
Huang, Y.; Chen, B. -Q.; Wang, C. +6 more
We present new three-dimensional (3D) interstellar dust reddening maps of the Galactic plane in three colours, E(G - KS), E(GBP - GRP), and E(H - KS). The maps have a spatial angular resolution of 6 arcmin and covers over 7000 deg2 of the Galactic plane for Galactic longitude 0° < l < 36…