Search Publications

Feasibility of Gallium Nitride for Astronomical Charge-Coupled Devices
DOI: 10.1007/s11664-024-11335-y Bibcode: 2024JEMat..53.6456A

Seabroke, George M.; Aggarwal, Anmol; Puri, Nitin K.

All astronomical missions use charge-coupled devices (CCDs) as vital organs. Usually, silicon (Si) is preferred to build them, which does not perform well without enhancements such as anti-reflection (AR) coatings. Such devices exhibit poor performance in the large (> 800 nm) and small (< 500 nm) wavelength ranges, even with AR coatings. We …

2024 Journal of Electronic Materials
Gaia 0
Molecular gas budget of strongly magnified low-mass star-forming galaxies at cosmic noon
DOI: 10.1051/0004-6361/202451892 Bibcode: 2024A&A...692A.215C

Sharon, K.; Bayliss, M.; Mahler, G. +9 more

Aims. The aim of this study is to investigate the molecular gas content of strongly magnified low-mass star-forming galaxies (SFGs) around the cosmic noon period (z ∼ 2) through observations of carbon monoxide (CO) emission lines and dust continuum emission, both of which serve as tracers of molecular gas (H2). Methods. We observed 12 s…

2024 Astronomy and Astrophysics
eHST JWST 0
The stellar population of a z ∼ 3.25 Lyα-emitting group associated with a damped Lyα absorber
DOI: 10.1051/0004-6361/202450609 Bibcode: 2024A&A...691A.222P

Rafelski, Marc; Fumagalli, Michele; Fossati, Matteo +4 more

We present near-infrared observations, acquired with the Wide Field Camera 3 (WFC3) on board the Hubble Space Telescope (HST), of a Lyα-emitting double-clumped nebula at z ≈ 3.25 associated with a damped Lyα absorber (DLA). With the WFC3/F160W data we observe the stellar continuum around 3600 Å in the rest frame of a galaxy embedded in the west cl…

2024 Astronomy and Astrophysics
Gaia eHST 0
Probing the nova shock physics with future gamma-ray observations of the upcoming outburst from T Coronae Borealis
DOI: 10.1016/j.jheap.2024.07.007 Bibcode: 2024JHEAp..43..171Z

Liu, Ruo-Yu; Zheng, Jian-He; Zhang, Hai-Ming +2 more

Nova shocks behave like scaled-down supernova remnant shocks with a lifetime of only a few weeks or months, thereby providing a unique opportunity to study the dynamics of non-relativistic shocks as well as the shock acceleration physics. Recently, GeV and TeV gamma-ray emissions from an outburst of the recurrent nova RS Ophiuchi have been observe…

2024 Journal of High Energy Astrophysics
Gaia 0
ALMA Detection of Masers and Dasars in the Hydrogen Recombination Lines of the Planetary Nebula Mz3
DOI: 10.3847/1538-4357/ad77c6 Bibcode: 2024ApJ...974..250A

Gonçalves, Denise R.; Ueta, Toshiya; Akras, Stavros +5 more

The hydrogen recombination lines H30α, H40α, H42α, H50β, and H57γ and the underlying bremsstrahlung continuum emission were detected with ALMA in the bipolar nebula Mz3. The source was not spatially resolved, but the velocity profile of the H30α line shows clear indication of maser amplification, confirming previous reports of laser amplification …

2024 The Astrophysical Journal
Gaia 0
Distance and stellar parameter estimations of solar-like stars from the LAMOST spectroscopic survey
DOI: 10.1051/0004-6361/202450164 Bibcode: 2024A&A...691A.218S

Luo, A. -Li; Shen, Yue-Yue

Context. The Gaia mission has opened up a new era for the precise astrometry of stars, thus revolutionizing our understanding of the Milky Way. However, beyond a few kiloparseconds from the Sun, parallax measurements become less reliable, and even within 2 kpc, there still exist stars with large uncertainties. Aims. Our aim was to determine the di…

2024 Astronomy and Astrophysics
Gaia 0
Temporal Changes in the Infrared Spectra of Magellanic Carbon Stars
DOI: 10.3390/galaxies12050061 Bibcode: 2024Galax..12...61S

Eriksson, K.; Sahai, R.; Höfner, S. +9 more

The Medium-Resolution Spectrometer on the Mid-Infrared Instrument on the JWST obtained spectra of three carbon stars in the Large Magellanic Cloud. Two of the spectra differ significantly from spectra obtained ∼16–19 years earlier with the Infrared Spectrograph on the Spitzer Space Telescope. The one semi-regular variable among the three has chang…

2024 Galaxies
JWST 0
Stellar population astrophysics with the TNG. Abundance analysis of nearby red giants and red clump stars: Combining high-resolution spectroscopy and asteroseismology
DOI: 10.1051/0004-6361/202348133 Bibcode: 2024A&A...684A..85V

Miglio, Andrea; Bragaglia, Angela; Lucatello, Sara +4 more

Context. Asteroseismology, a powerful approach for obtaining internal structure and stellar properties, requires surface temperature and chemical composition information to determine mass and age. High-resolution spectroscopy is a valuable technique for precise stellar parameters (including surface temperature) and for an analysis of the chemical …

2024 Astronomy and Astrophysics
Gaia 0
Using CSST and ejecta-wind interaction in type II-P supernovae to constrain the wind-mass loss of red supergiant stars
DOI: 10.1051/0004-6361/202349123 Bibcode: 2024A&A...689A.246L

Chen, Xuefei; Dessart, Luc; Luo, Jingxiao +1 more

The properties of H-rich, type II-plateau supernova (SN II-P) progenitors remain uncertain, and this is primarily due to the complexities associated with red supergiant (RSG) mass loss. Recent studies have suggested that the interaction of the ejecta with a standard RSG wind should produce unambiguous signatures in the optical (e.g., a broad, boxy…

2024 Astronomy and Astrophysics
eHST 0
Detection of High-frequency Pulsation in WR 135: Investigation of Stellar Wind Dynamics
DOI: 10.3847/1538-3881/ad77d0 Bibcode: 2024AJ....168..199K

Mathew, Blesson; Baug, Tapas; Das, Ramkrishna +2 more

We report the detection of high-frequency pulsations in WR 135 from short-cadence (10 minute) optical photometric and spectroscopic time series surveys. The harmonics up to the sixth order are detected from the integrated photometric flux variations, while the comparatively weaker eighth harmonic is detected from the strengths of the emission line…

2024 The Astronomical Journal
Gaia 0