Search Publications

Constraints on a mixed model of dark matter particles and primordial black holes from the galactic 511 keV line
DOI: 10.1088/1475-7516/2021/03/057 Bibcode: 2021JCAP...03..057C

Cai, Rong-Gen; Ding, Yu-Chen; Yang, Xing-Yu +1 more

The galactic 511 keV gamma-ray line has been observed since 1970's, and was identified as the result of electron-positron annihilation, but the origin of such positrons is still not clear. Apart from the astrophysical explanations, the possibilities that such positrons come from dark matter (DM) annihilation are also widely studied. Primordial bla…

2021 Journal of Cosmology and Astroparticle Physics
INTEGRAL 51
Size and structures of disks around very low mass stars in the Taurus star-forming region
DOI: 10.1051/0004-6361/202038983 Bibcode: 2021A&A...645A.139K

Pascucci, I.; Testi, L.; Scholz, A. +7 more

Context. The discovery of giant planets orbiting very low mass stars (VLMS) and the recent observed substructures in disks around VLMS is challenging planet formation models. Specifically, radial drift of dust particles is a catastrophic barrier in these disks, which prevents the formation of planetesimals and therefore planets.
Aims: We aim …

2021 Astronomy and Astrophysics
Gaia 51
Low-redshift compact star-forming galaxies as analogues of high-redshift star-forming galaxies
DOI: 10.1051/0004-6361/202039772 Bibcode: 2021A&A...646A.138I

Schaerer, D.; Thuan, T. X.; Izotov, Y. I. +3 more

We compare the relations among various integrated characteristics of ∼25 000 low-redshift (z ≲ 1.0) compact star-forming galaxies (CSFGs) from Data Release 16 (DR16) of the Sloan Digital Sky Survey and of high-redshift (z ≳ 1.5) star-forming galaxies (SFGs) with respect to oxygen abundances, stellar masses M, far-UV absolute magnitudes…

2021 Astronomy and Astrophysics
eHST 51
Giant Planets, Tiny Stars: Producing Short-period Planets around White Dwarfs with the Eccentric Kozai-Lidov Mechanism
DOI: 10.3847/1538-4357/ac22a9 Bibcode: 2021ApJ...922....4S

Gaudi, B. Scott; Naoz, Smadar; Stephan, Alexander P.

The recent discoveries of WD J091405.30+191412.25 (WD J0914 hereafter), a white dwarf (WD) likely accreting material from an ice-giant planet, and WD 1856+534 b (WD 1856 b hereafter), a Jupiter-sized planet transiting a WD, are the first direct evidence of giant planets orbiting WDs. However, for both systems, the observations indicate that the pl…

2021 The Astrophysical Journal
Gaia 51
Molecules with ALMA at Planet-forming Scales (MAPS). XIX. Spiral Arms, a Tail, and Diffuse Structures Traced by CO around the GM Aur Disk
DOI: 10.3847/1538-4365/ac143e Bibcode: 2021ApJS..257...19H

Zhang, Ke; Kalas, Paul; Wilner, David J. +28 more

The concentric gaps and rings commonly observed in protoplanetary disks in millimeter continuum emission have lent the impression that planet formation generally proceeds within orderly, isolated systems. While deep observations of spatially resolved molecular emission have been comparatively limited, they are increasingly suggesting that some dis…

2021 The Astrophysical Journal Supplement Series
Gaia Herschel eHST 51
Zero-metallicity Hypernova Uncovered by an Ultra-metal-poor Star in the Sculptor Dwarf Spheroidal Galaxy
DOI: 10.3847/2041-8213/ac0dc2 Bibcode: 2021ApJ...915L..30S

Helmi, Amina; Tolstoy, Eline; Hill, Vanessa +9 more

Although true metal-free "Population III" stars have so far escaped discovery, their nature, and that of their supernovae, is revealed in the chemical products left behind in the next generations of stars. Here we report the detection of an ultra-metal-poor star in the Sculptor dwarf spheroidal galaxy AS0039. With [Fe/H]LTE = -4.11, it …

2021 The Astrophysical Journal
Gaia 51
A precise asteroseismic age and metallicity for HD 139614: a pre-main-sequence star with a protoplanetary disc in Upper Centaurus-Lupus
DOI: 10.1093/mnras/stab144 Bibcode: 2021MNRAS.502.1633M

Bedding, Timothy R.; White, Timothy R.; Murphy, Simon J. +2 more

HD 139614 is known to be a ∼14-Myr-old, possibly pre-main-sequence star in the Sco-Cen OB association in the Upper Centaurus-Lupus subgroup, with a slightly warped circumstellar disc containing ring structures hinting at one or more planets. The star's chemical abundance pattern is metal-deficient except for volatile elements, which places it in t…

2021 Monthly Notices of the Royal Astronomical Society
Gaia 51
Evolution of Accretor Stars in Massive Binaries: Broader Implications from Modeling ζ Ophiuchi
DOI: 10.3847/1538-4357/ac29c5 Bibcode: 2021ApJ...923..277R

Renzo, M.; Götberg, Y.

Most massive stars are born in binaries close enough for mass transfer episodes. These modify the appearance, structure, and future evolution of both stars. We compute the evolution of a 100-day-period binary, consisting initially of a 25 M star and a 17 M star, which experiences stable mass transfer. We focus on the impa…

2021 The Astrophysical Journal
Gaia 51
Mock light-cones and theory friendly catalogues for the CANDELS survey
DOI: 10.1093/mnras/stab231 Bibcode: 2021MNRAS.502.4858S

Ferguson, Henry C.; Somerville, Rachel S.; Yung, L. Y. Aaron +9 more

We present mock catalogues created to support the interpretation of the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS). We extract haloes along past light-cones from the Bolshoi Planck dissipationless N-body simulations and populate these haloes with galaxies using two different independently developed semi-analytic models of g…

2021 Monthly Notices of the Royal Astronomical Society
eHST 50
Molecules with ALMA at Planet-forming Scales (MAPS). XII. Inferring the C/O and S/H Ratios in Protoplanetary Disks with Sulfur Molecules
DOI: 10.3847/1538-4365/ac2583 Bibcode: 2021ApJS..257...12L

Zhang, Ke; Wilner, David J.; Ménard, François +24 more

Sulfur-bearing molecules play an important role in prebiotic chemistry and planet habitability. They are also proposed probes of chemical ages, elemental C/O ratio, and grain chemistry processing. Commonly detected in diverse astrophysical objects, including the solar system, their distribution and chemistry remain, however, largely unknown in pla…

2021 The Astrophysical Journal Supplement Series
Gaia 50