Search Publications
Extinction of Taurus, Orion, Perseus, and California Molecular Clouds Based on the LAMOST, 2MASS, and Gaia Surveys. I. 3D Extinction and Structure
Jiang, Biwei; Zhao, He; Sun, Mingxu +1 more
The 3D extinction and structure are studied for the Taurus, Orion, Perseus, and California molecular clouds based on the LAMOST spectroscopy. Stellar color excess is calculated with the intrinsic color index derived from the atmospheric parameters in the LAMOST DR8 catalog and the observed color index in the Gaia EDR3 and the 2MASS PSC. In combina…
The ALPINE-ALMA [CII] survey: Double stellar population and active galactic nucleus activity in a galaxy at z ∼ 5.5
Pozzi, F.; Schaerer, D.; Marques-Chaves, R. +16 more
Context. GDS J033218.92-275302.7 (here GS-14) is a z ∼ 5.5 galaxy with unusual UV spectral features that have been interpreted as signatures of either a double stellar population or of an active galactic nucleus (AGN). GS-14 was detected in [C II] 158 µm as part of the ALPINE survey and was found to be the galaxy with the lowest molecular ga…
A crystallizing white dwarf in a sirius-like quadruple system
Vanderburg, Andrew; Blouin, Simon; Bédard, Antoine +1 more
The observational signature of core crystallization of white dwarfs has recently been discovered. However, the magnitude of the crystallization-powered cooling delay required to match observed white dwarfs is larger than predicted by conventional models, requiring additional mechanisms of energy release in white dwarf interiors. The most ideal ben…
WEAVE-StePS: A stellar population survey using WEAVE at WHT
Bolzonella, M.; Gullieuszik, M.; Moretti, A. +45 more
Context. The upcoming new generation of optical spectrographs on four-meter-class telescopes will provide valuable opportunities for forthcoming galaxy surveys through their huge multiplexing capabilities, excellent spectral resolution, and unprecedented wavelength coverage.
Aims: WEAVE is a new wide-field spectroscopic facility mounted on th…
Observational Signatures of Electron-driven Chromospheric Evaporation in a White-light Flare
Warmuth, Alexander; Li, Dong; Ning, Zongjun +7 more
We investigate observational signatures of explosive chromospheric evaporation during a white-light flare (WLF) that occurred on 2022 August 27. Using the moment analysis, bisector techniques, and the Gaussian fitting method, redshifted velocities of less than 20 km s‑1 are detected in low-temperature spectral lines of Hα, C I, and Si I…
3D tomography of the giant Lyα nebulae of z ≈ 3-5 radio-loud AGN
Noirot, Gaël; Lehnert, Matthew D.; De Breuck, Carlos +12 more
Lyα emission nebulae are ubiquitous around high-redshift galaxies and are tracers of the gaseous environment on scales out to ≳100 pkpc (proper kiloparsec). High-redshift radio galaxies (HzRGs, type-2 radio-loud quasars) host large-scale nebulae observed in the ionised gas differ from those seen in other types of high-redshift quasars. In this wor…
A catalogue of unusually long thermonuclear bursts on neutron stars
Degenaar, N.; in't Zand, J. J. M.; Kuulkers, E. +10 more
Rare, energetic (long) thermonuclear (Type I) X-ray bursts are classified either as intermediate-duration or 'supern' bursts, based on their duration. Intermediate-duration bursts lasting a few to tens of minutes are thought to arise from the thermonuclear runaway of a relatively thick (≈1010 g cm-2) helium layer, while super…
Chromospheric thermodynamic conditions from inversions of complex Mg II h & k profiles observed in flares
De Pontieu, Bart; Sainz Dalda, Alberto
The flare activity of the Sun has been studied for decades, using both space- and ground-based telescopes. The former have mainly focused on the corona, while the latter have mostly been used to investigate the conditions in the chromosphere and photosphere. The Interface Region Imaging Spectrograph (IRIS) instrument has served as a gateway betwee…
Colour jumps across the spiral arms of Hubble Ultra Deep Field galaxies
González-Lópezlira, Rosa A.; Martínez-García, Eric E.; Puerari, Ivânio
We have measured, at various wavelengths, the spiral arm pitch angles of a sample of distant spiral galaxies from the Hubble Space Telescope eXtreme Deep Field (XDF). According to density wave (DW) theory, we should detect colour jumps from red-to-blue across the spiral arms. Colour jumps are a consequence of large-scale shocks, which also generat…
Dust-buried Compact Sources in the Dwarf Galaxy NGC 4449
Ji, Zhiyuan; Smith, Linda J.; Calzetti, Daniela +10 more
Multiwavelength images from the Hubble Space Telescope covering the wavelength range 0.27-1.6 µm show that the central area of the nearby dwarf galaxy NGC 4449 contains several tens of compact sources that are emitting in the hydrogen recombination line Paβ (1.2818 µm) but are only marginally detected in Hα (0.6563 µm) and undete…