Evidence for a compact object in the aftermath of the extragalactic transient AT2018cow
The brightest Fast Blue Optical Transients (FBOTs) are mysterious extragalactic explosions that may represent a new class of astrophysical phenomena. Their fast time to maximum brightness of less than a week and decline over several months and atypical optical spectra and evolution are difficult...
| Main Authors: | , , , , , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Springer Science and Business Media LLC
2022
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| Online Access: | https://hdl.handle.net/1721.1/141438 |
| _version_ | 1826214988863242240 |
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| author | Pasham, Dheeraj R Ho, Wynn CG Alston, William Remillard, Ronald Ng, Mason Gendreau, Keith Metzger, Brian D Altamirano, Diego Chakrabarty, Deepto Fabian, Andrew Miller, Jon Bult, Peter Arzoumanian, Zaven Steiner, James F Strohmayer, Tod Tombesi, Francesco Homan, Jeroen Cackett, Edward M Harding, Alice |
| author2 | MIT Kavli Institute for Astrophysics and Space Research |
| author_facet | MIT Kavli Institute for Astrophysics and Space Research Pasham, Dheeraj R Ho, Wynn CG Alston, William Remillard, Ronald Ng, Mason Gendreau, Keith Metzger, Brian D Altamirano, Diego Chakrabarty, Deepto Fabian, Andrew Miller, Jon Bult, Peter Arzoumanian, Zaven Steiner, James F Strohmayer, Tod Tombesi, Francesco Homan, Jeroen Cackett, Edward M Harding, Alice |
| author_sort | Pasham, Dheeraj R |
| collection | MIT |
| description | The brightest Fast Blue Optical Transients (FBOTs) are mysterious
extragalactic explosions that may represent a new class of astrophysical
phenomena. Their fast time to maximum brightness of less than a week and
decline over several months and atypical optical spectra and evolution are
difficult to explain within the context of core-collapse of massive stars which
are powered by radioactive decay of Nickel-56 and evolve more slowly. AT2018cow
(at redshift of 0.014) is an extreme FBOT in terms of rapid evolution and high
luminosities. Here we present evidence for a high-amplitude quasi-periodic
oscillation (QPO) of AT2018cow's soft X-rays with a frequency of 224 Hz (at
3.7$\sigma$ significance level or false alarm probability of 0.02%) and
fractional root-mean-squared amplitude of >30%. This signal is found in the
average power density spectrum taken over the entire 60-day outburst and
suggests a highly persistent signal that lasts for a billion cycles. The high
frequency (rapid timescale) of 224 Hz (4.4 ms) argues for a compact object in
AT2018cow, which can be a neutron star or black hole with a mass less than 850
solar masses. If the QPO is the spin period of a neutron star, we can set
limits on the star's magnetic field strength. Our work highlights a new way of
using high time-resolution X-ray observations to study FBOTs. |
| first_indexed | 2024-09-23T16:14:29Z |
| format | Article |
| id | mit-1721.1/141438 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T16:14:29Z |
| publishDate | 2022 |
| publisher | Springer Science and Business Media LLC |
| record_format | dspace |
| spelling | mit-1721.1/1414382023-01-25T20:41:38Z Evidence for a compact object in the aftermath of the extragalactic transient AT2018cow Pasham, Dheeraj R Ho, Wynn CG Alston, William Remillard, Ronald Ng, Mason Gendreau, Keith Metzger, Brian D Altamirano, Diego Chakrabarty, Deepto Fabian, Andrew Miller, Jon Bult, Peter Arzoumanian, Zaven Steiner, James F Strohmayer, Tod Tombesi, Francesco Homan, Jeroen Cackett, Edward M Harding, Alice MIT Kavli Institute for Astrophysics and Space Research The brightest Fast Blue Optical Transients (FBOTs) are mysterious extragalactic explosions that may represent a new class of astrophysical phenomena. Their fast time to maximum brightness of less than a week and decline over several months and atypical optical spectra and evolution are difficult to explain within the context of core-collapse of massive stars which are powered by radioactive decay of Nickel-56 and evolve more slowly. AT2018cow (at redshift of 0.014) is an extreme FBOT in terms of rapid evolution and high luminosities. Here we present evidence for a high-amplitude quasi-periodic oscillation (QPO) of AT2018cow's soft X-rays with a frequency of 224 Hz (at 3.7$\sigma$ significance level or false alarm probability of 0.02%) and fractional root-mean-squared amplitude of >30%. This signal is found in the average power density spectrum taken over the entire 60-day outburst and suggests a highly persistent signal that lasts for a billion cycles. The high frequency (rapid timescale) of 224 Hz (4.4 ms) argues for a compact object in AT2018cow, which can be a neutron star or black hole with a mass less than 850 solar masses. If the QPO is the spin period of a neutron star, we can set limits on the star's magnetic field strength. Our work highlights a new way of using high time-resolution X-ray observations to study FBOTs. 2022-03-31T14:34:22Z 2022-03-31T14:34:22Z 2022-02 2022-03-31T14:17:45Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/141438 Pasham, Dheeraj R, Ho, Wynn CG, Alston, William, Remillard, Ronald, Ng, Mason et al. 2022. "Evidence for a compact object in the aftermath of the extragalactic transient AT2018cow." Nature Astronomy, 6 (2). en 10.1038/s41550-021-01524-8 Nature Astronomy Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Springer Science and Business Media LLC arXiv |
| spellingShingle | Pasham, Dheeraj R Ho, Wynn CG Alston, William Remillard, Ronald Ng, Mason Gendreau, Keith Metzger, Brian D Altamirano, Diego Chakrabarty, Deepto Fabian, Andrew Miller, Jon Bult, Peter Arzoumanian, Zaven Steiner, James F Strohmayer, Tod Tombesi, Francesco Homan, Jeroen Cackett, Edward M Harding, Alice Evidence for a compact object in the aftermath of the extragalactic transient AT2018cow |
| title | Evidence for a compact object in the aftermath of the extragalactic transient AT2018cow |
| title_full | Evidence for a compact object in the aftermath of the extragalactic transient AT2018cow |
| title_fullStr | Evidence for a compact object in the aftermath of the extragalactic transient AT2018cow |
| title_full_unstemmed | Evidence for a compact object in the aftermath of the extragalactic transient AT2018cow |
| title_short | Evidence for a compact object in the aftermath of the extragalactic transient AT2018cow |
| title_sort | evidence for a compact object in the aftermath of the extragalactic transient at2018cow |
| url | https://hdl.handle.net/1721.1/141438 |
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