Search Publications
The Complex Nature of Magnetic Element Transport in the Quiet Sun: The Lévy-walk Character
Giannattasio, F.; Berrilli, F.; Consolini, G. +1 more
The study of the dynamic properties of small-scale magnetic fields in the solar photosphere (magnetic elements, MEs) provides a fundamental tool to investigate some still unknown aspects of turbulent convection, and gain information on the spatial and temporal scales of evolution of the magnetic field in the quiet Sun. We track the MEs in a set of…
High-mass Star Formation in the nearby Region G352.630-1.067. I. Parallax
Chen, Xi; Xu, Ye; Zhang, Bo +5 more
Young or forming high-mass stars that are nearby and not within a cluster environment have the potential to provide fundamental insights into star formation. In this paper we report such a candidate (G352.630-1.067), for which we have measured the distance through very long baseline interferometry parallax observations of the associated 6.7 GHz cl…
Exploring the Interstellar Medium Using an Asymmetric X-Ray Dust Scattering Halo
Li, Guangxing; Jin, Chichuan; Ponti, Gabriele +1 more
SWIFT J1658.2-4242 is an X-ray transient discovered recently in the Galactic plane, with severe X-ray absorption corresponding to an equivalent hydrogen column density of ∼2 × 1023 cm-2. Using new Chandra and XMM-Newton data, we discover a strong X-ray dust scattering halo around it. The halo profile can be well fitted by the…
Constraining X-Ray Coronal Size with Transverse Motion of AGN Ultra-fast Outflows
Tombesi, Francesco; Fukumura, Keigo
One of the canonical physical properties of ultra-fast outflows (UFOs) seen in a diverse population of active galactic nuclei is its seemingly very broad width (i.e., Δv ≳ 10,000 km s-1), a feature often required for X-ray spectral modeling. While unclear to date, this condition is occasionally interpreted and justified as internal turb…
The Habitability of GJ 357D: Possible Climate and Observability
Pallé, E.; Kaltenegger, L.; Luque, R. +5 more
The GJ 357 system harbors three planets orbiting a bright, nearby M2.5V star at 9.44 pc. The innermost planet, GJ 357b (TOI-562.01), is a hot transiting Earth-sized planet with Earth-like density, which receives about 12 times the irradiation Earth receives from the Sun, and was detected using data from TESS. Radial velocities discovered two more …
Emission-line Metallicities from the Faint Infrared Grism Survey and VLT/MUSE
Finkelstein, Steven L.; Hathi, Nimish; Windhorst, Rogier +20 more
We derive direct-measurement gas-phase metallicities of 7.4< 12+{log}({{O}}/{{H}})< 8.4 for 14 low-mass emission-line galaxies at 0.3 < z < 0.8 identified in the Faint Infrared Grism Survey. We use deep slitless G102 grism spectroscopy of the Hubble Ultra Deep Field, dispersing light from all objects in the field at wavelengths between…
The First Candidate Colliding-wind Binary in M33
Williams, Benjamin F.; Massey, Philip; Levesque, Emily M. +1 more
We present the detection of the first candidate colliding-wind binary (CWB) in M33, located in the giant H II region NGC 604. The source was first identified in archival Chandra imaging as a relatively soft X-ray point source, with the likely primary star determined from precise astrometric alignment between archival Hubble Space Telescope and Cha…
Water and OH Emission from the Inner Disk of a Herbig Ae/Be Star
Najita, Joan R.; Brittain, Sean D.; Carr, John S. +2 more
We report the detection of hot H2O and OH emission from the Herbig Ae/Be star HD 101412 using the Cryogenic Infrared Echelle Spectrograph on the Very Large Telescope. Previous studies of Herbig Ae/Be stars have shown the presence of OH around some of these sources, but H2O has proven more elusive. While marginal water emissio…
Awakening of the Fast-spinning Accreting Be/X-Ray Pulsar A0538-66
Mereghetti, Sandro; Santangelo, Andrea; Ducci, Lorenzo
A0538-66 is a Be/X-ray binary (Be/XRB) hosting a 69 ms pulsar It emitted bright X-ray outbursts with peak luminosity up to ∼1039 erg s-1 during the first years after its discovery in 1977. Since then, it was always seen in quiescence or during outbursts with L x ≲ 4 × 1037 erg s-1. In 2018 we …
A Multi-epoch X-Ray Study of the Spiral Galaxy NGC 7331
Kong, Albert K. H.; Jin, Ruolan
X-ray point sources in galaxies are dominated by X-ray binaries (XRBs) that are variables or transients, and whether their variability would alter the X-ray luminosity functions (XLFs) is still in debate. Here we report on NGC 7331 as an example to test this with seven Chandra observations. Their detection limit is 7 × 1037 erg s-1…