Search Publications
Constraints on Primordial Magnetic Fields from High Redshift Stellar Mass Density
Li, Shang; Zhang, Qile; Tan, Xiu-Hui +1 more
Primordial magnetic fields (PMFs) play a pivotal role in influencing small-scale fluctuations within the primordial density field, thereby enhancing the matter power spectrum within the context of the ΛCDM model at small scales. These amplified fluctuations accelerate the early formation of galactic halos and stars, which can be observed through a…
A multiwavelength study of Swift J0503.7-2819: a chimeric magnetic CV
Dewangan, G. C.; Buckley, D. A. H.; Singh, Kulinder Pal +7 more
We present multiwavelength temporal and spectral characteristics of a magnetic cataclysmic variable (MCV) Swift J0503.7-2819, using far ultraviolet and X-ray data from AstroSat, supplemented with optical data from the Southern African Large Telescope and X-ray data from the XMM-Newton and Swift observatories. The X-ray modulations at 4897.6657 s a…
Evolved Massive Stars at Low Metallicity. VII. The Lower Mass Limit of the Red Supergiant Population in the Large Magellanic Cloud
Tian, Hao; Yang, Ming; Gao, Jian +8 more
The precise definition of the lower mass limit of red supergiant stars (RSGs) is an open question in astrophysics and does not attract much attention. Here, we assemble a spectroscopic evolved cool star sample with 6602 targets, including RSGs, asymptotic giant branch stars, and red giant branch stars, in the Large Magellanic Cloud based on Gaia D…
The polarisation properties of the HD 181327 debris ring. Evidence for sub-micron particles from scattered light observations
Lasue, J.; Pinte, C.; Ménard, F. +26 more
Context. Polarisation is a powerful remote-sensing tool to study the nature of particles scattering the starlight. It is widely used to characterise interplanetary dust particles in the Solar System and increasingly employed to investigate extrasolar dust in debris discs' systems.
Aims: We aim to measure the scattering properties of the dust …
The CARMENES search for exoplanets around M dwarfs. Revisiting the GJ 581 multi-planetary system with new Doppler measurements from CARMENES, HARPS, and HIRES
Amado, P. J.; Caballero, J. A.; Reiners, A. +18 more
Context. GJ 581 is a nearby M dwarf known to host a packed multiple planet system composed of two super-Earths and a Neptune-mass planet. We present new orbital analyses of the GJ 581 system, utilizing recent radial velocity (RV) data obtained from the CARMENES spectrograph combined with newly reprocessed archival data from the HARPS and HIRES spe…
The Cosmic Ultraviolet Baryon Survey (CUBS). VIII. Group Environment of the Most Luminous Quasars at z ≈ 1
Johnson, Sean D.; Petitjean, Patrick; Zahedy, Fakhri S. +11 more
We investigate the group-scale environment of 15 luminous quasars (luminosity L 3000 > 1046 erg s‑1) from the Cosmic Ultraviolet Baryon Survey (CUBS) at redshift z ≈ 1. Using the Multi Unit Spectroscopic Explorer integral field spectrograph on the Very Large Telescope, we conduct a deep galaxy redshift survey in…
Physically Motivated Deep Learning to Superresolve and Cross Calibrate Solar Magnetograms
Maloney, Shane A.; Muñoz-Jaramillo, Andrés; Wright, Paul J. +7 more
Superresolution (SR) aims to increase the resolution of images by recovering detail. Compared to standard interpolation, deep learning-based approaches learn features and their relationships to leverage prior knowledge of what low-resolution patterns look like in higher resolution. Deep neural networks can also perform image cross-calibration by l…
The TESS-Keck Survey. XVIII. A Sub-Neptune and Spurious Long-period Signal in the TOI-1751 System
Kostov, Veselin B.; Bieryla, Allyson; Mayo, Andrew W. +37 more
We present and confirm TOI-1751 b, a transiting sub-Neptune orbiting a slightly evolved, solar-type, metal-poor star (T eff = 5996 ± 110 K, $\mathrm{log}(g)=4.2\pm 0.1$ , V = 9.3 mag, [Fe/H] = ‑0.40 ± 0.06 dex) every 37.47 days. We use TESS photometry to measure a planet radius of ${2.77}_{-0.07}^{+0.15}\,{R}_{\oplus }$ . We also use bo…
The giant outburst of EXO 2030+375. I. Spectral and pulse profile evolution
Wilms, J.; Pottschmidt, K.; Kretschmar, P. +12 more
The Be X-ray binary EXO 2030+375 went through its third recorded giant outburst from June 2021 to early 2022. We present the results of both spectral and timing analysis based on NICER monitoring, covering the 2−10 keV flux range from 20 to 310 mCrab. Dense monitoring with observations carried out about every second day and a total exposure time o…
Constraining Time Variations in Enceladus's Water-vapor Plume with Near-infrared Spectra from Cassini's Visual and Infrared Mapping Spectrometer
Hedman, M. M.; Bockelée-Morvan, D.; Capaccioni, F. +2 more
Water vapor produces a series of diagnostic emission lines in the near-infrared between 2.60 and 2.75 µm. The Visual and Infrared Mapping Spectrometer (VIMS) on board the Cassini spacecraft detected this emission signal from Enceladus's plume, and so VIMS observations provide information about the variability of the plume's water-vapor conte…