Search Publications

High-frequency Magnetic Fluctuations in Space Plasmas and the Role of Electron Landau Damping
DOI: 10.3847/2041-8213/ac4740 Bibcode: 2022ApJ...924L..26C

Telloni, Daniele; Vecchio, Antonio; Lepreti, Fabio +1 more

While low-frequency plasma fluctuations in the interplanetary space have been successfully described in the framework of classical turbulence, high-frequency fluctuations still represent a challenge for theoretical models. At these scales, kinetic plasma processes are at work, but although some of them have been identified in spacecraft measuremen…

2022 The Astrophysical Journal
Cluster 14
Multimessenger Constraints on Magnetic Fields in Merging Black Hole-Neutron Star Binaries
DOI: 10.3847/1538-4357/ac4bdb Bibcode: 2022ApJ...927...56D

Haiman, Zoltán; D'Orazio, Daniel J.; Vigna-Gómez, Alejandro +2 more

The LIGO-Virgo-KAGRA Collaboration recently detected gravitational waves (GWs) from the merger of black hole-neutron star (BHNS) binary systems GW200105 and GW200115. No coincident electromagnetic (EM) counterparts were detected. While the mass ratio and BH spin in both systems were not sufficient to tidally disrupt the NS outside the BH event hor…

2022 The Astrophysical Journal
INTEGRAL 14
Metallicity Distribution Function of the Eridanus II Ultra-faint Dwarf Galaxy from Hubble Space Telescope Narrowband Imaging
DOI: 10.3847/1538-4357/ac3665 Bibcode: 2022ApJ...925....6F

Dolphin, Andrew E.; Martin, Nicolas; Starkenburg, Else +9 more

We use deep narrowband CaHK (F395N) imaging taken with the Hubble Space Telescope (HST) to construct the metallicity distribution function (MDF) of Local Group ultra-faint dwarf galaxy Eridanus II (Eri II). When combined with archival F475W and F814W data, we measure metallicities for 60 resolved red giant branch stars as faint as m F475W

2022 The Astrophysical Journal
Gaia eHST 14
A Possible 250 s X-Ray Quasi-periodicity in the Fast Blue Optical Transient AT2018cow
DOI: 10.1088/1674-4527/ac9c4b Bibcode: 2022RAA....22l5016Z

Tao, Lian; Zhang, Liang; Shu, Xinwen +11 more

The fast blue optical transients (FBOTs) are a new population of extragalactic transients of unclear physical origin. A variety of mechanisms has been proposed including failed supernova explosion, shock interaction with a dense medium, young magnetar, accretion onto a compact object and stellar tidal disruption event, but none is conclusive. Here…

2022 Research in Astronomy and Astrophysics
XMM-Newton 14
A First Look into the Nature of JWST/MIRI 7.7 µm Sources from SMACS 0723
DOI: 10.3847/2041-8213/aca014 Bibcode: 2022ApJ...940L..24I

Rinaldi, Pierluigi; Caputi, Karina I.; Iani, Edoardo +1 more

Until now, our knowledge of the extragalactic universe at mid-infrared (mid-IR) wavelengths (>5 µm) was limited to rare active galactic nuclei and the brightest normal galaxies up to z ~ 3. The advent of JWST with its Mid-Infrared Instrument (MIRI) will revolutionize the ability of the mid-IR regime as a key wavelength domain to probe the…

2022 The Astrophysical Journal
Gaia eHST JWST 14
Distance and age of the massive stellar cluster Westerlund 1. I. Parallax method using Gaia-EDR3
DOI: 10.1093/mnras/stac2374 Bibcode: 2022MNRAS.516.1289N

Damineli, Augusto; Navarete, Felipe; Almeida, Leonardo A. +2 more

Westerlund 1 (Wd 1) is one of the most massive young star clusters in the Milky Way. Although relevant for star formation and evolution, its fundamental parameters are not yet very well constrained. We aim to derive an accurate distance and provide constraints on the cluster age. We used the photometric and astrometric information available in the…

2022 Monthly Notices of the Royal Astronomical Society
Gaia 14
HST/WFC3 Complete Phase-resolved Spectroscopy of White-dwarf-brown-dwarf Binaries WD 0137 and EPIC 2122
DOI: 10.3847/1538-3881/ac3095 Bibcode: 2022AJ....163...17Z

Mayorga, L. C.; Lothringer, Joshua D.; Apai, Dániel +7 more

Brown dwarfs in close-in orbits around white dwarfs offer an excellent opportunity to investigate properties of fast-rotating, tidally locked, and highly irradiated atmospheres. We present Hubble Space Telescope Wide Field Camera 3 G141 phase-resolved observations of two brown-dwarf-white-dwarf binaries: WD 0137-349 and EPIC 212235321. Their 1.1-1…

2022 The Astronomical Journal
Gaia eHST 14
Microlensing Events in the Galactic Plane Using the Zwicky Transient Facility
DOI: 10.3847/1538-4357/ac51cc Bibcode: 2022ApJ...927..150R

Duev, Dmitry A.; Riddle, Reed; Mróz, Przemek +10 more

Microlensing is a powerful technique to study the Galactic population of "dark" objects such as exoplanets both bound and unbound, brown dwarfs, low-luminosity stars, old white dwarfs, and neutron stars, and it is almost the only way to study isolated stellar-mass black holes. The majority of previous efforts to search for gravitational microlensi…

2022 The Astrophysical Journal
Gaia 14
The OmegaWhite survey for short-period variable stars - VII. High amplitude short-period blue variables
DOI: 10.1093/mnras/stac1000 Bibcode: 2022MNRAS.513.2215R

Ramsay, Gavin; Buckley, David A. H.; Kupfer, Thomas +11 more

Blue Large-Amplitude Pulsators (BLAPs) are a relatively new class of blue variable stars showing periodic variations in their light curves with periods shorter than a few tens of minutes and amplitudes of more than 10 per cent. We report nine blue variable stars identified in the OmegaWhite survey conducted using ESO's VST, which shows a periodic …

2022 Monthly Notices of the Royal Astronomical Society
Gaia 14
The tidal evolution of the Fornax dwarf spheroidal and its globular clusters
DOI: 10.1093/mnras/stab2912 Bibcode: 2022MNRAS.509.5330B

Fattahi, Azadeh; Navarro, Julio F.; Errani, Raphaël +2 more

The dark matter content of the Fornax dwarf spheroidal galaxy inferred from its kinematics is substantially lower than expected from LCDM cosmological simulations. We use N-body simulations to examine whether this may be the result of Galactic tides. We find that, despite improved proper motions from the Gaia mission, the pericentric distance of F…

2022 Monthly Notices of the Royal Astronomical Society
Gaia 14