Search Publications
Searching for Black Hole Candidates by LAMOST and ASAS-SN
Liu, Jifeng; Bai, Yu; Gu, Wei-Min +13 more
Most dynamically confirmed stellar-mass black holes (BHs) and their candidates were originally selected from X-ray outbursts. In the present work, we search for BH candidates in the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) survey using the spectra along with photometry from the All Sky Automated Survey for SuperNovae (ASA…
Extended X-Ray Study of M49: The Frontier of the Virgo Cluster
Mernier, F.; Churazov, E.; Maccarone, T. J. +10 more
The M49 group, residing outside the virial radius of the Virgo cluster, is falling onto the cluster from the south. We report results from deep XMM-Newton mosaic observations of M49. Its hot gas temperature is 0.8 keV at the group center and rises to 1.5 keV beyond the brightest group galaxy (BGG). The group gas extends to radii of ∼300 kpc to the…
The Herschel-PACS North Ecliptic Pole Survey
Goto, Tomotsugu; Kim, Seong Jin; Pearson, Chris +9 more
A detailed analysis of Herschel/Photoconductor Array Camera and Spectrometer (PACS) observations at the North Ecliptic Pole is presented. High-quality maps, covering an area of 0.44 deg2, are produced and then used to derive potential candidate source lists. A rigorous quality-control pipeline has been used to create final legacy catalo…
The complex evolution of the X-ray binary transient MAXI J1807+132 along the decay of its discovery outburst
Russell, D. M.; Armas Padilla, M.; Jiménez-Ibarra, F. +6 more
MAXI J1807+132 is an X-ray transient discovered during the decay of an outburst in 2017. We present optical and X-ray monitoring of the source over more than 125 d, from outburst to quiescence. The outburst decay is characterized by the presence of several reflares with a quasi-periodic recurrence time of ∼6.5 d. We detect broad H and He emission …
Wide-area photometric and astrometric (Gaia DR2) study of the young cluster NGC 6530
Micela, G.; Sciortino, S.; Prisinzano, L. +1 more
Context. NGC 6530 is a young cluster, with a complex morphology and star-formation history. We present a statistical study of its global properties, using a new, large list of candidate members down to masses of 0.2-0.4 M⊙ and Gaia DR2 astrometry.
Aims: We consider a larger sky region compared to previous studies, to investigate th…
A Detailed Study of the Most Relaxed SPT-selected Galaxy Clusters: Properties of the Cool Core and Central Galaxy
Schrabback, T.; Hlavacek-Larrondo, J.; Bayliss, M. +14 more
We present a multi-wavelength analysis of the four most relaxed clusters in the South Pole Telescope 2500 deg2 survey, which lie at 0.55 < z < 0.75. This study, which utilizes new, deep data from the Chandra X-ray Observatory and Hubble Space Telescope, along with ground-based spectroscopy from Gemini and Magellan, improves signif…
Frequency-Distance Structure of Solar Radio Sources Observed by LOFAR
Browning, Philippa; Gordovskyy, Mykola; Kontar, Eduard +1 more
Low-frequency radio observations make it possible to study the solar corona at distances up to 2-3 R ⊙. Frequency of plasma emission is a proxy for electron density of the emitting plasma and, therefore, observations of solar radio bursts can be used to probe the density structure of the outer corona. In this study, positions of solar r…
Radius Inflation at Low Rossby Number in the Hyades Cluster
Stassun, Keivan G.; Somers, Garrett; Jaehnig, Karl
Radius inflation continues to be explored as a peculiar occurrence among magnetically active, low-mass stars. Recently, Somers & Stassun showed that radius inflation among low-mass stars in the young open cluster M45 (Pleiades Cluster) is correlated to the rotation rate: faster rotators are more inflated. Here we extend that work to a sample o…
The Dynamics, Structure, and Fate of a Young Cluster during Gas Dispersal: Hectoschelle, Chandra, Spitzer, and Gaia Observations of Cep OB3b
Jeffries, R. D.; Megeath, S. T.; Gutermuth, R. A. +5 more
We present a study of the kinematics and structure of the Cep OB3b cluster based on new spectra obtained with the Hectoschelle spectrograph on the MMT and data from Spitzer, Chandra, and Gaia. At a distance of 819 ± 16 pc, Cep OB3b is one of the closest examples of a young (∼3-5 Myr), large (∼3000 total members) cluster at the late stages of gas d…
Models of the Mass-ejection Histories of Pre-planetary Nebulae. III. The Shaping of Lobes by Post-AGB Winds
Frank, Adam; Balick, Bruce; Liu, Baowei
We develop a physical framework for interpreting high-resolution images and kinematics of pre-planetary nebulae (“prePNe”). We use hydrodynamical models to infer the historical properties of fast collimated nuclear flows (“jet”) that successfully form hollow, candle-shaped lobes over ≈103 yr, including the density, momenta, and geometry…