Search Publications
ZZ Piscis Austrinus (ZZ PsA): a bright red nova progenitor and the instability mass ratio of contact binary stars
Filipović, Miroslav D.; Tothill, N. F. H.; Wadhwa, Surjit S. +4 more
ZZ Piscis Austrinus (ZZ PsA) is a neglected bright southern contact binary system with maximum V magnitude of 9.26. We present the first multiband photometric analysis and find the system to be in deep contact (>95 per cent) with an extremely low mass ratio of 0.078. The primary has a mass of 1.213 M⊙ in keeping with its reported spe…
Understanding the Impacts of Stellar Companions on Planet Formation and Evolution: A Survey of Stellar and Planetary Companions within 25 pc
Macintosh, Bruce; Fulton, Benjamin J.; Hirsch, Lea A. +10 more
We explore the impact of outer stellar companions on the occurrence rate of giant planets detected with radial velocities. We searched for stellar and planetary companions to a volume-limited sample of solar-type stars within 25 pc. Using adaptive optics imaging observations from the Lick 3 m and Palomar 200″ Telescopes, we characterized the multi…
The 450 Day X-Ray Monitoring of the Changing-look AGN 1ES 1927+654
Altamirano, D.; Fabian, A. C.; Gandhi, P. +16 more
1ES 1927+654 is a nearby active galactic nucleus (AGN) that underwent a changing-look event in early 2018, developing prominent broad Balmer lines that were absent in previous observations. We have followed up this object in the X-rays with an ongoing campaign that started in 2018 May and that includes 265 NICER (for a total of 678 ks) and 14 Swif…
The PAU Survey: an improved photo-z sample in the COSMOS field
Alarcon, Alex; Carretero, Jorge; Castander, Francisco J. +21 more
We present - and make publicly available - accurate and precise photometric redshifts in the ACS footprint from the COSMOS field for objects with iAB ≤ 23. The redshifts are computed using a combination of narrow-band photometry from PAUS, a survey with 40 narrow bands spaced at $100\,\mathring{\rm A}$ intervals covering the range from …
Uncertainties in the Galactic Dark Matter distribution: An update
Iocco, Fabio; Benito, María; Cuoco, Alessandro
We present here a quantitative estimate of the impact of uncertainties of astrophysical nature on the determination of the dark matter distribution within our Galaxy, the Milky Way. Based on an update of a previous analysis, this work is motivated by recent new determinations of astrophysical quantities of relevance - such as the Galactic paramete…
Evolution of the local spiral structure of the Milky Way revealed by open clusters
Hao, C. J.; Xu, Y.; Hou, L. G. +6 more
The structure and evolution of the spiral arms of our Milky Way are basic but long-standing questions in astronomy. In particular, the lifetime of spiral arms is still a puzzle and has not been well constrained from observations. In this work, we aim to inspect these issues using a large catalogue of open clusters. We compiled a catalogue of 3794 …
New Horizons Observations of the Cosmic Optical Background
Buratti, Bonnie J.; Singer, Kelsi N.; McKinnon, William B. +27 more
We used existing data from the New Horizons Long-range Reconnaissance Imager (LORRI) to measure the optical-band (0.4 ≲ λ ≲ 0.9 µm) sky brightness within seven high-Galactic latitude fields. The average raw level measured while New Horizons was 42-45 au from the Sun is 33.2 ± 0.5 nW m-2 sr-1. This is ∼10× as dark as the…
CO Multi-line Imaging of Nearby Galaxies (COMING). IX. 12CO(J = 2-1)/12CO(J = 1-0) line ratio on kiloparsec scales
Kobayashi, Masato I. N.; Kuno, Nario; Miyamoto, Yusuke +8 more
While molecular gas mass is usually derived from 12CO(J = 1-0)—the most fundamental line for exploring molecular gas—it is often derived from 12CO(J = 2-1) assuming a constant 12CO(J = 2-1) $/$ 12CO(J = 1-0) line ratio (R2/1). We present variations of R2/1 and effects of the assumpt…
The Parallax Zero-point of Gaia Early Data Release 3 from LAMOST Primary Red Clump Stars
Huang, Yang; Beers, Timothy C.; Yuan, Haibo +1 more
We present an independent examination of the parallax zero-point of the Third Gaia Early Data Release (hereafter EDR3), using the LAMOST primary red clump (PRC) stellar sample. A median parallax offset of around 26 µas, slightly larger than that found by examination of distant quasars, is found for both the five- and six-parameter solutions …
The TW Hya Rosetta Stone Project. III. Resolving the Gaseous Thermal Profile of the Disk
Zhang, Ke; Öberg, Karin; Walsh, Catherine +16 more
The thermal structure of protoplanetary disks is a fundamental characteristic of the system that has wide-reaching effects on disk evolution and planet formation. In this study, we constrain the 2D thermal structure of the protoplanetary disk TW Hya structure utilizing images of seven CO lines. This includes new ALMA observations of 12C…