Search Publications
Missions
Journals
Publication Years
FLAME: Fitting Lyα absorption lines using machine learning
Vivek, M.; Jalan, P.; Khaire, V. +1 more
We introduce FLAME, a machine-learning algorithm designed to fit Voigt profiles to H I Lyman-alpha (Lyα) absorption lines using deep convolutional neural networks. FLAME integrates two algorithms: the first determines the number of components required to fit Lyα absorption lines, and the second calculates the Doppler parameter b, the H I column de…
AGN populations in the local Universe: Their alignment with the main sequence, stellar population characteristics, accretion efficiency, and the impact of AGN feedback
Georgantopoulos, I.; Mountrichas, G.; Akylas, A. +3 more
In this study, we used a sample of 338 galaxies - within the redshift range of 0.02 < z < 0.1 drawn from the Sloan Digital Sky Survey (SDSS) - for which there are available classifications based on their emission line ratios. We identified and selected Compton-thick (CT) AGN through the use of X-ray and infrared luminosities at 12 µm. …
The first ground-based detection of the 752 GHz water line in local ultraluminous infrared galaxies using APEX-SEPIA
Aalto, Susanne; Martín, Sergio; Zhang, Zhi-Yu +10 more
We report the first ground-based detection of the water line p-H2O (211-202) at 752.033 GHz in three z < 0.08 ultraluminous infrared galaxies (ULIRGs): IRAS 06035-7102, IRAS 17207-0014, and IRAS 09022-3615. Using the Atacama Pathfinder EXperiment (APEX), with its Swedish-ESO PI Instrument for APEX (SEPIA) band-9…
Seeds and sequences of element abundances in solar energetic particle events
Reames, Donald V.
Solar energetic particles (SEPs) in the small "impulsive" events, primarily accelerated during magnetic reconnection in solar jets, have strong enhancements of the abundances of increasingly heavy elements. In contrast, the shock acceleration of ambient coronal plasma in most large "gradual" SEP events produces flat or decreasing abundances vs. el…
Chandra X-Ray Observations of PSR J1849-0001, Its Pulsar Wind Nebula, and the TeV Source HESS J1849-000
Kargaltsev, Oleg; Klingler, Noel; Yang, Hui +4 more
We obtained a 108 ks Chandra X-ray Observatory (CXO) observation of PSR J1849-0001 and its pulsar wind nebula (PWN) coincident with the TeV source HESS J1849-000. By analyzing the new and old (archival) CXO data, we resolved the pulsar from the PWN, explored the PWN morphology on arcsecond and arcminute scales, and measured the spectra of differen…
HD 222237 b: a long-period super-Jupiter around a nearby star revealed by radial-velocity and Hipparcos-Gaia astrometry
Butler, R. Paul; Rice, Malena; Wittenmyer, Robert A. +16 more
Giant planets on long-period orbits around the nearest stars are among the easiest to directly image. Unfortunately these planets are difficult to fully constrain by indirect methods, e.g. transit and radial velocity (RV). In this study, we present the discovery of a super-Jupiter, HD 222237 b, orbiting a star located
Probing the energy and luminosity-dependent spectro-timing properties of RX J0440.9+4431 with AstroSat
Paul, Biswajit; Ratheesh, Ajay; Sharma, Rahul +3 more
The Be/X-ray binary pulsar RX J0440.9+4431 went through a giant outburst in December 2022 with a peak flux of
Atmospheric Abundances and Bulk Properties of the Binary Brown Dwarf Gliese 229Bab from JWST/MIRI Spectroscopy
Zhang, Yapeng; Perrin, Marshall D.; Knutson, Heather A. +8 more
We present JWST/Mid Infrared Instrument (MIRI) low-resolution spectroscopy (4.75–14 µm) of the first known substellar companion, Gliese 229Bab, which was recently resolved into a tight binary brown dwarf. Previous atmospheric retrieval studies modeling Gliese 229B as a single brown dwarf have reported anomalously high carbon-to-oxygen ratios…
Cassini's CDA observes a variety of dust populations just outside Saturn's main rings
Postberg, Frank; Hillier, Jon K.; Srama, Ralf +5 more
Before the end of its mission, the Cassini spacecraft orbited Saturn in a series of highly inclined elliptical 'Ring-Grazing' orbits (RGO). During the RGO, the spacecraft passed repeatedly through the ring plane outside the F ring, near the orbits of Janus and Epimetheus, at an average relative speed of ~20 km s-1. For the first time, C…
Ulysses spacecraft in situ detections of cometary dust trails
Krüger, Harald; Grün, Eberhard; Strub, Peter
The Ulysses spacecraft was launched in 1990 and, after a Jupiter swing-by in 1992, became the first interplanetary spacecraft orbiting the Sun on a highly inclined trajectory with an inclination of 79 ∘ . The spacecraft was equipped with an impact ionization dust detector which provided 17 years of in situ dust measurements in interplan…