23 pages, 18 figures (including appendix). MNRAS (submitted). Comments welcome
During the core collapse of massive stars that do not undergo a canonical energetic explosion, some of the hydrogen envelope of a red supergiant (RSG) progenitor may infall onto the newborn black hole (BH). Within the Athena++ framework, we perform three-dimensional, hydrodynamical simulations of idealized models of supergiant convection and collapse in order to assess whether the infall of the convective envelope can give rise to rotationally-supported material, even if the star has zero angular momentum overall. Our dimensionless, polytropic models are applicable to the optically-thick hydrogen envelope of non-rotating RSGs and cover a factor of 20 in stellar radius. At all radii, the specific angular momentum due to random convective flows implies associated circularization radii of 10 - 1500 times the innermost stable circular orbit of the BH. During collapse, the angular momentum vector of the convective flows is approximately conserved and is slowly varying on the timescale relevant to forming disks at small radii. Our results indicate that otherwise failed explosions of RSGs lead to the formation of rotationally-supported flows that are capable of driving outflows to large radii and powering observable transients. When the BH is able to accrete most of the hydrogen envelope, the final BH spin parameter is $\sim$ 0.5, even though the star is non-rotating. For fractional accretion of the envelope, the spin parameter is generally lower and never exceeds 0.8. We discuss the implications of our results for transients produced by RSG collapse to a black hole.
The diffuse far-ultraviolet (FUV) background has received considerable attention from astronomers since the seventies. The initial impetus came from the hope of detecting UV radiation from the hot intergalactic medium. The central importance of the FUV background to the physics (heating and ionization) of the diffuse atomic phases motivated the next generation of experiments. The consensus view is that the diffuse FUV emission at high latitudes has three components: stellar FUV reflected by dust grains (diffuse galactic light or DGL), FUV from other galaxies (extra-galactic background light, EBL) and a component of unknown origin. During the eighties, there was some discussion that decaying dark matter particles produced FUV radiation. In this paper I investigate production of FUV photons by conventional sources: the Galactic Hot Ionized Medium (line emission), two photon emission from the Galactic Warm Ionized Medium and low-velocity shocks, and Lyman-beta excitation of hydrogen at several locales in the Solar System (the interplanetary medium, the exosphere and thermosphere of Earth). I conclude that two thirds of the third component can be explained by the sum of the processes listed above.
15 pages, 9 figures, Submitted to ApJ
37 pages, 28 figures, accepted for publication in Astronomy & Astrophysics
Accepted for publication in The Astrophysical Journal. 16 pages, 6 figures
36+8 pages, 15+6 figures, main results in Figs. 8 and 12
10 pages, 6 figures, submitted to MNRAS, comments are welcome
Preprint of an article published in Nature Astronomy. The final authenticated version is available online at: this https URL
5 pages, 2 figures, 1 appendix table. accepted for publication in A&A
39 pages, 14 figures and 6 tables
13 pages, 12 figures, 5 tables, Submitted to Astronomy and Astrophysics
9 pages, 4 figures (+1 page appendix); submitted to AAS Journals
8 Pages, 9 Figures, submitted to MNRAS. Comments welcome
10 pages, 9 figures
13 pages, 10 figures. Submitted to MNRAS
15 pages, 10 figures, to appear in ApJ
18 pages, 13 figures, 4 tables; submitted to The Astronomical Journal (AJ)
18 pages, 7 figures; accepted for publication in MNRAS
Presented at the 37th International Cosmic Ray Conference (ICRC 2021). See arXiv:2107.06966 for all IceCube contributions
10 pages, 10 figures, 9 tables
Accepted for publication in MNRAS. 21 pages
8 pages, 2 Figures, 2 Tables
Astrophysical Journal, in press. 24 pages, 7 figures
21 pages, 18 figures
310 pages, 16 figures, 21 tables, accepted to be published in The Astrophysical Journal
9 pages, 5 figures, 1 table, accepted to be published in ApJ
12 pages, 10 figures; published by ApJ
23 pages, 11 figures
Presented at the 37th International Cosmic Ray Conference (ICRC 2021). See arXiv:2107.06966 for all IceCube contributions
34 pages, 17 figures, Accepted for publication in APJS
Presented at the 37th International Cosmic Ray Conference (ICRC 2021). See arXiv:2107.06966 for all IceCube contributions
13 pages, 6 figures. To be published in MNRAS
19 pages, 10 figures, submitted to MNRAS; comments welcome
Accepted for publication in ApJ
Presented at the 37th International Cosmic Ray Conference (ICRC 2021). See arXiv:2107.06966 for all IceCube contributions
18 pages, 13 figures
23 pages, 41 figures, Review paper about matched filters and their applications
19 pages, 15 figures, 4 tables. Accepted for publication in MNRAS
11 pages, 8 figures, 3 tables
Presented at the 37th International Cosmic Ray Conference (ICRC 2021). See arXiv:2107.06966 for all IceCube contributions. 11 pages, 6 figures
11 pages, 6 figures, 1 appendix; accepted for publication in MNRAS
11 pages, 6 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Society
22 pages, 19 figures. This is the Accepted Manuscript version of an article accepted for publication in The Astrophysical Journal Supplement Series. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it
27 pages, 6 figures. arXiv admin note: text overlap with arXiv:1408.5237
To be published in RNAAS
43 pages, 18 figures and 8 tables
12 pages, 7 figures, accepted for publication in MNRAS
17 pages, 8 figures, 7 tables, accepted for publication in A&A
14 pages, 7 figures
Submitted to Proceedings for the 40th Annual Symposium of the Society for Astronomical Sciences, SAS-2021, eds. John C. Martin, Robert K. Buchheim, Robert M. Gill, Wayne Greene, and Robert Stephens, June 2021
Forthcoming article, Astronomy and Astrophysics
11 pages, 10 figures
21 pages, 17 figures, 1 table. Submitted to MNRAS
17 pages, 20 figures, submitted to A&A 15.Feb.2021, accepted for publication in A&A 20.Jul.2021
6 pages, 2 figures, 2 tables, accepted for publication on Monthly Notices of the Royal Astronomical Society
Presented at the 37th International Cosmic Ray Conference (ICRC 2021). See arXiv:2107.06966 for all IceCube contributions
9 pages, 8 figures
7 pages, 7 figures
6 pages, 3 figures. Contribution to the 2021 Gravitation session of the 55th Rencontres de Moriond
Presented at the 37th International Cosmic Ray Conference (ICRC 2021). See arXiv:2107.06966 for all IceCube contributions
11 pages, 1 figure, appears in Proc. SPIE
Submitted to ApJS
Presented at the 37th International Cosmic Ray Conference (ICRC 2021). See arXiv:2107.06966 for all IceCube contributions
Presented at the 37th International Cosmic Ray Conference (ICRC 2021). See arXiv:2107.06966 for all IceCube contributions
13 pages, 7 figures
25+5 pages, 9+2 figures
5 pages, 4 figures, 2 supplements
8 pages, 8 figures, 1 table, accepted for publication in PASJ
19 pages, 13 figures
arXiv admin note: substantial text overlap with arXiv:1707.09190
10 Pages, 13 figure, Accepted for the Small Satellite Conference 2021
25 pages, 19 figures, 3 tables, accepted for publication in JINST
9 pages, 6 figures, Contribution to Proceedings of BSM 2021, Egypt, Based on: arXiv:2010.14621
Accepted in General Relativity and Gravitation journal, Springer
27 pages, 2 figures
6 pages, 3 figures. arXiv admin note: text overlap with arXiv:2009.07182