Search Publications
Survey of Multiple Populations in Globular Clusters among Very-low-mass Stars
Milone, A. P.; Cordoni, G.; Marino, A. F. +14 more
Recent work has shown that near-infrared (NIR) Hubble Space Telescope (HST) photometry allows us to disentangle multiple populations (MPs) among M dwarfs of globular clusters (GCs) and to investigate this phenomenon in very-low-mass (VLM) stars. Here, we present the color-magnitude diagrams of nine GCs and the open cluster NGC 6791 in the F110W an…
Constraining the Nature of the 18 min Periodic Radio Transient GLEAM-X J162759.5-523504.3 via Multiwavelength Observations and Magneto-thermal Simulations
de Martino, D.; Rea, N.; Buckley, D. A. H. +14 more
We observed the periodic radio transient GLEAM-X J162759.5-523504.3 (GLEAM-X J1627) using the Chandra X-ray Observatory for about 30 ks on 2022 January 22-23, simultaneously with radio observations from the Murchison Widefield Array, MeerKAT, and the Australia Telescope Compact Array. Its radio emission and 18 min periodicity led the source to be …
The Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER). II. The Spatially Resolved Recent Star Formation History of M33
Bell, Eric F.; Williams, Benjamin F.; Choi, Yumi +11 more
We measure the spatially resolved recent star formation history (SFH) of M33 using optical images taken with the Hubble Space Telescope as part of the Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER) survey. The area covered by the observations used in this analysis covers a de-projected area of ~38 kpc2 and …
A New Magnetic Parameter of Active Regions Distinguishing Large Eruptive and Confined Solar Flares
Hou, Yijun; Li, Ting; Yang, Shuhong +3 more
With the aim of investigating how the magnetic field in solar active regions (ARs) controls flare activity, i.e., whether a confined or eruptive flare occurs, we analyze 106 flares of Geostationary Operational Environmental Satellite class ≥M1.0 during 2010-2019. We calculate mean characteristic twist parameters α FPIL within the "flari…
Insight-HXMT, NuSTAR, and INTEGRAL Data Show Disk Truncation in the Hard State of the Black Hole X-Ray Binary MAXI J1820+070
Zdziarski, Andrzej A.; You, Bei; Szanecki, Michał +2 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 joint spectra from HXMT, NuSTAR, and INTEGRAL. We find an overall agreement between the spectra from all three satellites. Satisfactory fits to the data require substantial spectral complexity, with our models …
VLT/MUSE Observations of SDSS J1029+2623: Toward a High-precision Strong Lensing Model
Brammer, Gabriel B.; Acebron, Ana; Nonino, Mario +9 more
We present a strong lensing analysis of the galaxy cluster SDSS J1029+2623 at z = 0.588, one of the few currently known lens clusters with multiple images of a background (z = 2.1992) quasar with a measured time delay. We use archival Hubble Space Telescope multiband imaging and new Multi Unit Spectroscopic Explorer follow-up spectroscopy to build…
Turbulence in Milky Way Star-forming Regions Traced by Young Stars and Gas
Kounkel, Marina; Li, Hui; Zheng, Yong +3 more
The interstellar medium (ISM) is turbulent over vast scales and in various phases. In this paper, we study turbulence with different tracers in four nearby star-forming regions: Orion, Ophiuchus, Perseus, and Taurus. We combine the APOGEE-2 and Gaia surveys to obtain the full six-dimensional measurements of positions and velocities of young stars …
Residual Abundances in GALAH DR3: Implications for Nucleosynthesis and Identification of Unique Stellar Populations
Buder, Sven; Weinberg, David H.; Johnson, Jennifer A. +3 more
We investigate the [X/Mg] abundances of 16 elements for 82,910 Galactic disk stars from GALAH+ DR3. We fit the median trends of low-Ia and high-Ia populations with a two-process model, which describes stellar abundances in terms of a prompt core-collapse and delayed Type-Ia supernova component. For each sample star, we fit the amplitudes of these …
Causes and Consequences of Magnetic Complexity Changes within Interplanetary Coronal Mass Ejections: A Statistical Study
Lugaz, Noé; Scolini, Camilla; Winslow, Réka M. +3 more
We present the first statistical analysis of complexity changes affecting the magnetic structure of interplanetary coronal mass ejections (ICMEs), with the aim of answering the questions: How frequently do ICMEs undergo magnetic complexity changes during propagation? What are the causes of such changes? Do the in situ properties of ICMEs differ de…
Current Challenges in Cepheid Distance Calibrations Using Gaia Early Data Release 3
Madore, Barry F.; Freedman, Wendy L.; Lee, Abigail J. +1 more
Using parallaxes from Gaia Early Data Release 3 (EDR3), we determine multi-wavelength BVI c , JHK s , and [3.6] and [4.5] micron absolute magnitudes for 37 nearby Milky Way Cepheids, covering the period range between 5 and 60 days. We apply these period-luminosity relations to Cepheids in the Large and Small Magellanic Clou…