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Related papers: NEXUS: A Search for Nuclear Variability with the F…

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We present first results of JWST Cycle 1 and 2 observations of Sgr A* using NIRCam taken simultaneously at 2.1 and 4.8 micron for a total of ~48 hours over seven different epochs in 2023 and 2024. We find correlated variability at 2.1 and…

Astrophysics of Galaxies · Physics 2025-01-09 F. Yusef-Zadeh , H. Bushouse , R. G. Arendt , M. Wardle , J. M. Michail , C. J. Chandler

JWST holds great promise in characterizing atmospheres of transiting exoplanets, potentially providing insights into Earth-sized planets within the habitable zones of M dwarf host stars if photon-limited performance can be achieved. Here,…

Instrumentation and Methods for Astrophysics · Physics 2021-02-19 Everett Schlawin , Jarron Leisenring , Michael W. McElwain , Karl Misselt , Kenneth Don , Thomas P. Greene , Thomas Beatty , Nikolay Nikolov , Douglas Kelly , Marcia Rieke

Variability is a fundamental signature for active galactic nuclei (AGN) activity, and serve as an unbiased indicator for rapid instability happened near the center supermassive black hole (BH). Previous studies showed that AGN variability…

Astrophysics of Galaxies · Physics 2024-12-09 Wei Leong Tee , Xiaohui Fan , Feige Wang , Jinyi Yang

The quiescent spectrum of neutron star low-mass X-ray binaries typically consists of two components - a thermal component associated with emission from the neutron star surface, and a non-thermal power-law component whose origin is not well…

High Energy Astrophysical Phenomena · Physics 2015-03-25 A. R. Walsh , E. M. Cackett , F. Bernardini

We present a spectral variability study of the ultraluminous X-ray source NGC 4490 ULX-8 based on 14 Chandra, 6 XMM-Newton and 19 Swift-XRT observations obtained between 2000 and 2024. The X-ray spectra are modelled using absorbed power-law…

High Energy Astrophysical Phenomena · Physics 2026-05-25 Tarang Vashisht , Aru Beri , Tanuman Ghosh , Aman Upadhyay , Vikram Rana

The James Webb Space Telescope (JWST) has extended the frontier of galaxy detection to redshifts z>11, finding a high abundance of UV-bright sources that challenge theoretical models. However, most current results come from just a few…

The high angular resolution technique of non-redundant masking (NRM) or aperture masking interferometry (AMI) has yielded images of faint protoplanetary companions of nearby stars from the ground. AMI on James Webb Space Telescope (JWST)'s…

Instrumentation and Methods for Astrophysics · Physics 2015-06-23 Alexandra Z. Greenbaum , Laurent Pueyo , Anand Sivaramakrishnan , Sylvestre Lacour

Comparison of 8.4-GHz radio images of a sample of 11 early-type Seyfert galaxies with previous observations reveals possible variation in the nuclear radio flux density in 5 of them over a 7-yr period. We find no correlation between radio…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-28 C. G. Mundell , P. Ferruit , N. Nagar , A. S. Wilson

Context. X-ray spectral variability analyses of active galactic nuclei (AGN) with moderate luminosities and redshifts typically show a softer when brighter behaviour. Such a trend has rarely been investigated for high-luminosity AGNs ($…

Astrophysics of Galaxies · Physics 2017-04-12 R. Serafinelli , F. Vagnetti , R. Middei

The James Webb Space Telescope (JWST) North Ecliptic Pole (NEP) Time-Domain Field (TDF) has been monitored by NuSTAR and XMM-Newton with a regular cadence for five years starting in 2019. The survey has accumulated 3.5Ms of NuSTAR exposure…

Under the unified model for active galactic nuclei (AGNs), narrow-line (Type 2) AGNs are, in fact, broad-line (Type 1) AGNs but each with a heavily obscured accretion disk. We would therefore expect the optical continuum emission from Type…

The James Webb Space Telescope (JWST) will be launched in December 2021, with four instruments to perform imaging and spectroscopy. This paper presents work which is part of the Early Release Science (ERS) program "PDRs4All" aimed at…

Instrumentation and Methods for Astrophysics · Physics 2021-12-07 A. Canin , O. Berné , The PDRs4All ERS team

Low mass (sub)stellar objects represent the low end of the initial mass function, the transition to free-floating planets and a prominent interloper population in the search for high-redshift galaxies. Without proper motions or…

We present a 5 month NICER X-ray monitoring campaign for two low luminosity active galactic nuclei (LLAGNs) -- NGC 4594 and IC 1459 -- with complementary Swift and NuSTAR observations. Utilizing an absorbed power law and thermal source…

High Energy Astrophysical Phenomena · Physics 2025-03-17 Nicole M. Ford , Michael Nowak , Venkatessh Ramakrishnan , Daryl Haggard , Kristen Dage , Dhanya G. Nair , Chi-kwan Chan

We release fully reduced spectra obtained with NIRSpec onboard JWST as part of the GLASS-JWST Early Release Science Program and a follow-up Director's Discretionary Time program 2756. From these 263 spectra of 245 unique sources, acquired…

We present the JWST Emission Line Survey (JELS), a JWST imaging programme exploiting the wavelength coverage and sensitivity of NIRCam to extend narrow-band rest-optical emission line selection into the epoch of reionization (EoR) for the…

We present four galaxy scale lenses discovered in two JWST blank-fields: the ~ 54 arcmin^2 of the PEARLS North-Ecliptic-Pole Time-Domain Field (NEP TDF) and in the ~ 90 arcmin^2 of CEERS. We perform the search by visual inspection of NIRCam…