Search Publications
Intermediate-mass Stars Become Magnetic White Dwarfs
Caiazzo, Ilaria; Heyl, Jeremy; Richer, Harvey +8 more
When a star exhausts its nuclear fuel, it either explodes as a supernova or more quiescently becomes a white dwarf, an object about half the mass of our Sun with a radius of about that of the Earth. About one-fifth of white dwarfs exhibit the presence of magnetic fields, whose origin has long been debated as either the product of previous stages o…
CO, Water, and Tentative Methanol in η Carinae Approaching Periastron
Corcoran, Michael; Gull, Theodore R.; Damineli, Augusto +12 more
The complex circumstellar environment around the massive binary and luminous blue variable η Carinae is known to harbor numerous light molecules, emitting most strongly in rotational states with upper level energies to ∼300 K. In circumstellar gas, the complex organic molecule methanol (CH3OH) has been found almost exclusively around yo…
The Hyperluminous, Dust-obscured Quasar W2246-0526 at z = 4.6: Detection of Parsec-scale Radio Activity
Knudsen, Kirsten K.; Yang, Jun; An, Tao +4 more
WISE J224607.56-052634.9 (W2246-0526) is a hyperluminous (Lbol ≈ 1.7 × 1014 L⊙), dust-obscured, and radio-quiet quasar at redshift z = 4.6. It plays a key role in probing the transition stage between dusty starbursts and unobscured quasars in the coevolution of galaxies and supermassive black holes (SMBHs). To sear…
Kinematical Signs of Dust Trapping and Feedback in a Local Pressure Bump in the Protoplanetary Disk around HD 142527 Revealed with ALMA
Yen, Hsi-Wei; Gu, Pin-Gao
We analyzed the archival data of the continuum emission at six wavelengths from 3 to 0.4 mm and 13CO and C18O (1-0, 2-1, and 3-2) lines in the protoplanetary disk around HD 142527 obtained with the Atacama Large Millimeter/submillimeter Array. We performed fitting to the spectral energy distributions obtained at the six wavel…
Discovery of a Low-mass Companion Embedded in the Disk of the Young Massive Star MWC 297 with VLT/SPHERE
Manara, Carlo F.; Lodato, Giuseppe; Christiaens, Valentin +4 more
We report the discovery of a low-mass stellar companion around the young Herbig Be star MWC 297. We performed multi-epoch high-contrast imaging in the near-infrared with the Very Large Telescope (VLT)/Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument. The companion is found at a projected separation of 244.7 ± 13.2 au and a…
HD 145263: Spectral Observations of Silica Debris Disk Formation via Extreme Space Weathering?
Sitko, M. L.; Marengo, M.; Chen, C. H. +9 more
We report here time-domain infrared spectroscopy and optical photometry of the HD 145263 silica-rich circumstellar-disk system taken from 2003 through 2014. We find an F4V host star surrounded by a stable, massive 1022-1023 kg (MMoon to MMars) dust disk. No disk gas was detected, and the primary star was…
Mass-to-light Ratios of Spatially Resolved Stellar Populations in M31
Bell, Eric F.; Dolphin, Andrew E.; Williams, Benjamin F. +4 more
A galaxy's stellar mass-to-light ratio (M_{\star }/L) is a useful tool for converting luminosity to stellar mass (M_{\star }). However, the practical utility of M_{\star}/L inferred from stellar population synthesis (SPS) models is limited by mismatches between the real and assumed models for star-formation history (SFH) and dust geometry, both of…
DY Pegasi: An SX Phoenicis Star in a Binary System with an Evolved Companion
Xue, Hui-Fang; Niu, Jia-Shu
In this work, the photometric data from the American Association of Variable Star Observers are collected and analyzed on the SX Phoenicis star DY Pegasi (DY Peg). From the frequency analysis, we get three independent frequencies: f0 = 13.71249 c d-1, f1 = 17.7000 c d-1, and f2 = 18.138 c d
Fermi-LAT Observations of V549 Vel 2017: A Subluminous Gamma-Ray Nova?
Strader, Jay; Chomiuk, Laura; Munari, Ulisse +4 more
We report on the Fermi Large Area Telescope detection (with ≈5.7σ significance) as well as the multiwavelength analysis of the 2017 nova eruption V549 Vel. Unlike the recent shock-powered novae ASASSN-16ma and V906 Car, the optical and γ-ray light curves of V549 Vel show no correlation, likely implying relatively weak shocks in the eruption. Gaia …
The Star Formation Rate-Radius Connection: Data and Implications for Wind Strength and Halo Concentration
Barro, Guillermo; Ferguson, Henry C.; Grogin, Norman A. +26 more
This paper is one in a series that explores the importance of radius as a second parameter in galaxy evolution. The topic investigated here is the relationship between star formation rate (SFR) and galaxy radius ( ${R}_{{\rm{e}}}$ ) for main-sequence star-forming galaxies. The key observational result is that, over a wide range of stellar mass and…