Search Publications

Multiple Stellar Populations in Asymptotic Giant Branch Stars of Galactic Globular Clusters
DOI: 10.3847/1538-4357/abdfcf Bibcode: 2021ApJ...910....6L

Milone, A. P.; Cordoni, G.; Marino, A. F. +8 more

Multiple stellar populations (MPs) are a distinct characteristic of globular clusters (GCs). Their general properties have been widely studied among main-sequence, red giant branch (RGB), and horizontal branch (HB) stars, but a common framework is still missing at later evolutionary stages. We studied the MP phenomenon along the asymptotic giant b…

2021 The Astrophysical Journal
eHST 22
The Late-time Radio Behavior of Gamma-ray Burst Afterglows: Testing the Standard Model
DOI: 10.3847/1538-4357/abe76b Bibcode: 2021ApJ...911...14K

Fruchter, Andrew S.; Kangas, Tuomas

We examine a sample of 21 gamma-ray burst (GRB) afterglow light curves at radio frequencies and compare them to the X-ray and/or optical properties of the afterglows and to the predictions of the standard jet/fireball model. Our sample includes every Swift GRB with an X-ray light curve indicating a jet break and with a published radio light curve,…

2021 The Astrophysical Journal
eHST 22
A Near-infrared Survey of UV-excited Molecular Hydrogen in Photodissociation Regions
DOI: 10.3847/1538-4357/ac0899 Bibcode: 2021ApJ...919...27K

Kim, Hwihyun; Dinerstein, Harriet L.; Jaffe, Daniel T. +1 more

We present a comparative study of the near-infrared (NIR) H2 line emission from five regions near hot young stars: Sharpless 140, NGC 2023, IC 63, the Horsehead Nebula, and the Orion Bar. This emission originates in photodissociation or photon-dominated regions (PDRs), interfaces between photoionized and molecular gas near hot (O) stars…

2021 The Astrophysical Journal
Gaia 22
The Be Star 66 Ophiuchi: 60 Years of Disk Evolution
DOI: 10.3847/1538-4357/abed4c Bibcode: 2021ApJ...912...76M

Carciofi, A. C.; Mota, B. C.; Jones, C. E. +5 more

We use a time-dependent hydrodynamic code and a non-LTE Monte Carlo code to model disk dissipation for the Be star 66 Ophiuchi. We compiled 63 years of observations from 1957 to 2020 to encompass the complete history of the growth and subsequent dissipation of the star's disk. Our models are constrained by new and archival photometry, spectroscopy…

2021 The Astrophysical Journal
AKARI Gaia IUE 22
Most of the cool CGM of star-forming galaxies is not produced by supernova feedback
DOI: 10.1093/mnras/staa3759 Bibcode: 2021MNRAS.501.5575A

Afruni, Andrea; Fraternali, Filippo; Pezzulli, Gabriele

The characterization of the large amount of gas residing in the galaxy haloes, the so-called circumgalactic medium (CGM), is crucial to understand galaxy evolution across cosmic time. We focus here on the cool (T ~ 104 K) phase of this medium around star-forming galaxies in the local Universe, whose properties and dynamics are poorly un…

2021 Monthly Notices of the Royal Astronomical Society
eHST 22
New open clusters found by manual mining of data based on Gaia DR2
DOI: 10.1088/1674-4527/21/5/117 Bibcode: 2021RAA....21..117C

Casado, Juan

The physical nature of a series of 20 new open clusters is confirmed employing existing data on putative star members, mainly from the second Gaia Data Release (DR2). The clusters were discovered as overdensities of stars by visual inspection of either photographic DSS plates or proper motion plots of random source fields. The reported objects are…

2021 Research in Astronomy and Astrophysics
Gaia 22
Caltech-NRAO Stripe 82 Survey (CNSS). V. AGNs That Transitioned to Radio-loud State
DOI: 10.3847/1538-4357/abe62d Bibcode: 2021ApJ...914...22W

Gromadzki, Mariusz; Hallinan, Gregg; Ishwara-Chandra, C. H. +6 more

A recent multiyear Caltech-NRAO Stripe 82 Survey revealed a group of objects that appeared as new radio sources after >5-20 yr of absence. They are transient phenomena with respect to the Faint Images of the Radio Sky at Twenty Centimeters survey and constitute the first unbiased sample of renewed radio activity. Here we present a follow-up, ra…

2021 The Astrophysical Journal
XMM-Newton 22
Identifying Planetary Transit Candidates in TESS Full-frame Image Light Curves via Convolutional Neural Networks
DOI: 10.3847/1538-3881/abf4c6 Bibcode: 2021AJ....161..273O

Powell, Brian P.; Barclay, Thomas; Kruse, Ethan +8 more

The Transiting Exoplanet Survey Satellite (TESS) mission measured light from stars in ∼75% of the sky throughout its 2 yr primary mission, resulting in millions of TESS 30-minute-cadence light curves to analyze in the search for transiting exoplanets. To search this vast data trove for transit signals, we aim to provide an approach that both is co…

2021 The Astronomical Journal
Gaia 22
Flaring and Spot Activities on the Semi-detached Binary System KIC 06852488
DOI: 10.3847/1538-3881/abccd7 Bibcode: 2021AJ....161...46S

Shi, Xiang-dong; Qian, Sheng-bang; Li, Lin-jia +1 more

The continuous and unbroken time-series photometry data of Kepler and the Transiting Exoplanet Survey Satellite (TESS) provide a good opportunity to study the continuous variations in the light curve of binary stars. This paper reports the discoveries of the correlation between the two maxima on the light curve of KIC 06852488 and the correlation …

2021 The Astronomical Journal
Gaia 22
Hybrid Comptonization and Electron-Positron Pair Production in the Black-hole X-Ray Binary MAXI J1820+070
DOI: 10.3847/2041-8213/ac0147 Bibcode: 2021ApJ...914L...5Z

Poutanen, Juri; Zdziarski, Andrzej A.; Szanecki, Michał +6 more

We study X-ray and soft gamma-ray spectra from the hard state of the accreting black-hole binary MAXI J1820+070. We perform an analysis of two joint spectra from NuSTAR and INTEGRAL, covering the range of 3-650 keV, and of an average joint spectrum over the rise of the hard state, covering the 3-2200 keV range. The spectra are well modeled by Comp…

2021 The Astrophysical Journal
INTEGRAL 22