Search Publications
The NuSTAR Serendipitous Survey: The 80 Month Catalog and Source Properties of the High-energy Emitting Active Galactic Nucleus and Quasar Population
Noirot, Gaël; Brandt, William N.; Aird, James +32 more
We present a catalog of hard X-ray serendipitous sources detected in the first 80 months of observations by the Nuclear Spectroscopic Telescope Array (NuSTAR). The NuSTAR serendipitous survey 80 month (NSS80) catalog has an unprecedented ∼62 Ms of effective exposure time over 894 unique fields (a factor of 3 increase over the 40 month catalog, NSS…
Accretion rates of 42 nova-like stars with IUE and Gaia data
Selvelli, Pierluigi; Gilmozzi, Roberto
We analyzed more than 700 ultraviolet spectra of 45 nova-like stars (NLs) observed with the International Ultraviolet Explorer (IUE) satellite, obtaining reliable data for 42 of them. Combining these with the distances from the Gaia Early Data Release 3 (EDR3) and with results from the literature, for each object we determined the reddening E…
Multiple power-law tails in the density and column-density distribution in contracting star-forming clumps
Klessen, Ralf S.; Veltchev, Todor V.; Donkov, Sava +3 more
We present a numerical study of the evolution of power-law tails (PLTs) in the (column-)density distributions (N-PDF, ρ-PDF) in contracting star-forming clumps in primordial gas, without and with some initial rotational and/or turbulent support. In all considered runs multiple PLTs emerge shortly after the formation of the first protostar. The fir…
Comprehensive Synthesis of Magnetic Tornado: Cospatial Incidence of Chromospheric Swirls and Extreme-ultraviolet Brightening
Yokoyama, Takaaki; Bose, Souvik; Kuniyoshi, Hidetaka
Magnetic tornadoes, characterized as impulsive Alfvén waves initiated by photospheric vortices in intergranular lanes, are considered efficient energy channels to the corona. Despite their acknowledged importance for solar coronal heating, their observational counterparts from the corona have not been well understood. To address this issue, we use…
Application of Convolutional Neural Networks to time domain astrophysics. 2D image analysis of OGLE light curves
Bayo, A.; Angeloni, R.; Monsalves, N. +4 more
In recent years the amount of publicly available astronomical data has increased exponentially, with a remarkable example being large-scale multiepoch photometric surveys. This wealth of data poses challenges to the classical methodologies commonly employed in the study of variable objects. As a response, deep learning techniques are increasingly …
Stellar Population Astrophysics (SPA) with TNG. Fluorine abundances in seven open clusters
Bragaglia, A.; Sanna, N.; D'Orazi, V. +9 more
Context. The age, evolution, and chemical properties of the Galactic disk can be effectively ascertained using open clusters. Within the large program Stellar Populations Astrophysics at the Telescopio Nazionale Galileo, we specifically focused on stars in open clusters, to investigate various astrophysical topics, from the chemical content of ver…
Simba-C: the evolution of the thermal and chemical properties in the intragroup medium
Hough, Renier T.; Shao, Zhiwei; Cui, Weiguang +5 more
The newly updated GIZMO and Simba based simulation, Simba-C, with its new stellar feedback, chemical enrichment, and recalibrated AGN feedback, allows for a detailed study of the intragroup medium X-ray properties. We discuss the impact of various physical mechanisms, e.g. stellar and AGN feedback, and chemical enrichment, on the composition and t…
The impact of stellar metallicity on rotation and activity evolution in the Kepler field using gyro-kinematic ages
Amard, Louis; See, Victor; Lu, Yuxi (Lucy) +1 more
In recent years, there has been a push to understand how chemical composition affects the magnetic activity levels of main sequence low-mass stars. Results indicate that more metal-rich stars are more magnetically active for a given stellar mass and rotation period. This metallicity dependence has implications for how the rotation periods and acti…
From Chromospheric Evaporation to Coronal Rain: An Investigation of the Mass and Energy Cycle of a Flare
Antolin, Patrick; Şahin, Seray
Chromospheric evaporation (CE) and coronal rain (CR) represent two crucial phenomena encompassing the circulation of mass and energy during solar flares. While CE marks the start of the hot inflow into the flaring loop, CR marks the end, indicating the outflow in the form of cool and dense condensations. With the Interface Region Imaging Spectrogr…
First Detection of CO Isotopologues in a High-redshift Main-sequence Galaxy: Evidence of a Top-heavy Stellar Initial Mass Function
Fu, Xiaoting; Ivison, R. J.; Zhang, Zhi-Yu +5 more
Recent observations and theories have presented a strong challenge to the universality of the stellar initial mass function (IMF) in extreme environments. A notable example has been found for starburst conditions, where evidence favors a top-heavy IMF, i.e., there is a bias toward massive stars compared to the IMF that is responsible for the stell…