iPTF16fnl: A Faint and Fast Tidal Disruption Event in an E+A Galaxy
We present ground-based and Swift observations of iPTF16fnl, a likely tidal disruption event (TDE) discovered by the intermediate Palomar Transient Factory (iPTF) survey at 66.6 Mpc. The light curve of the object peaked at an absolute mag M[subscript g] = -17.2. The maximum bolometric luminosity (f...
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| Format: | Article |
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IOP Publishing
2017
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| Online Access: | http://hdl.handle.net/1721.1/112303 |
| _version_ | 1811093634513108992 |
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| author | Pasham, Dheeraj Ranga Reddy |
| author2 | MIT Kavli Institute for Astrophysics and Space Research |
| author_facet | MIT Kavli Institute for Astrophysics and Space Research Pasham, Dheeraj Ranga Reddy |
| author_sort | Pasham, Dheeraj Ranga Reddy |
| collection | MIT |
| description | We present ground-based and Swift observations of iPTF16fnl, a likely tidal disruption event (TDE) discovered by the intermediate Palomar Transient Factory (iPTF) survey at 66.6 Mpc. The light curve of the object peaked at an absolute mag M[subscript g] = -17.2. The maximum bolometric luminosity (from optical and UV) was L[subscript p] ≃ (1.0 ± 0.15) × 10[superscript 43] erg s[superscript -1], an order of magnitude fainter than any other optical TDE discovered so far. The luminosity in the first 60 days is consistent with an exponential decay, with L ∝ e [superscript -(t-t0)/τ], where t[subscript 0] = 57631.0 (MJD) and τ ≃ 15 days. The X-ray shows a marginal detection at L[subscript X] = 2.4[superscript 1.9][subscript -1.1] × 10[superscript 39] erg s[superscript -1] (Swift X-ray Telescope). No radio counterpart was detected down to 3σ, providing upper limits for monochromatic radio luminosities of νL [subscript ν] < 1.7 × 10[superscript 36] erg s[superscript -1] and νL[subscript ν] < 2.3 × 10[superscript 37] erg s[superscript -1] (Very Large Array, 6.1 and 22 GHz). The blackbody temperature, obtained from combined Swift UV and optical photometry, shows a constant value of 19,000 K. The transient spectrum at peak is characterized by broad He ii and Hα emission lines, with FWHMs of about 14,000 km s[superscript -1] and 10,000 km s[superscript -1], respectively. He i lines are also detected at λλ 5875 and 6678. The spectrum of the host is dominated by strong Balmer absorption lines, which are consistent with a post-starburst (E+A) galaxy with an age of ∼650 Myr and solar metallicity. The characteristics of iPTF16fnl make it an outlier on both luminosity and decay timescales, as compared to other optically selected TDEs. The discovery of such a faint optical event suggests a higher rate of tidal disruptions, as low-luminosity events may have gone unnoticed in previous searches. |
| first_indexed | 2024-09-23T15:48:13Z |
| format | Article |
| id | mit-1721.1/112303 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T15:48:13Z |
| publishDate | 2017 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/1123032022-10-02T04:14:00Z iPTF16fnl: A Faint and Fast Tidal Disruption Event in an E+A Galaxy Pasham, Dheeraj Ranga Reddy MIT Kavli Institute for Astrophysics and Space Research Pasham, Dheeraj Ranga Reddy We present ground-based and Swift observations of iPTF16fnl, a likely tidal disruption event (TDE) discovered by the intermediate Palomar Transient Factory (iPTF) survey at 66.6 Mpc. The light curve of the object peaked at an absolute mag M[subscript g] = -17.2. The maximum bolometric luminosity (from optical and UV) was L[subscript p] ≃ (1.0 ± 0.15) × 10[superscript 43] erg s[superscript -1], an order of magnitude fainter than any other optical TDE discovered so far. The luminosity in the first 60 days is consistent with an exponential decay, with L ∝ e [superscript -(t-t0)/τ], where t[subscript 0] = 57631.0 (MJD) and τ ≃ 15 days. The X-ray shows a marginal detection at L[subscript X] = 2.4[superscript 1.9][subscript -1.1] × 10[superscript 39] erg s[superscript -1] (Swift X-ray Telescope). No radio counterpart was detected down to 3σ, providing upper limits for monochromatic radio luminosities of νL [subscript ν] < 1.7 × 10[superscript 36] erg s[superscript -1] and νL[subscript ν] < 2.3 × 10[superscript 37] erg s[superscript -1] (Very Large Array, 6.1 and 22 GHz). The blackbody temperature, obtained from combined Swift UV and optical photometry, shows a constant value of 19,000 K. The transient spectrum at peak is characterized by broad He ii and Hα emission lines, with FWHMs of about 14,000 km s[superscript -1] and 10,000 km s[superscript -1], respectively. He i lines are also detected at λλ 5875 and 6678. The spectrum of the host is dominated by strong Balmer absorption lines, which are consistent with a post-starburst (E+A) galaxy with an age of ∼650 Myr and solar metallicity. The characteristics of iPTF16fnl make it an outlier on both luminosity and decay timescales, as compared to other optically selected TDEs. The discovery of such a faint optical event suggests a higher rate of tidal disruptions, as low-luminosity events may have gone unnoticed in previous searches. National Science Foundation (U.S.) (Grant 1545949) 2017-11-28T16:36:16Z 2017-11-28T16:36:16Z 2017-07 2017-05 2017-11-17T16:03:10Z Article http://purl.org/eprint/type/JournalArticle 1538-4357 0004-637X http://hdl.handle.net/1721.1/112303 Blagorodnova, N., et al. “iPTF16fnl: A Faint and Fast Tidal Disruption Event in an E+A Galaxy.” The Astrophysical Journal, vol. 844, no. 1, July 2017, p. 46. © 2017 The American Astronomical Society http://dx.doi.org/10.3847/1538-4357/aa7579 The Astrophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf IOP Publishing IOP Publishing |
| spellingShingle | Pasham, Dheeraj Ranga Reddy iPTF16fnl: A Faint and Fast Tidal Disruption Event in an E+A Galaxy |
| title | iPTF16fnl: A Faint and Fast Tidal Disruption Event in an E+A Galaxy |
| title_full | iPTF16fnl: A Faint and Fast Tidal Disruption Event in an E+A Galaxy |
| title_fullStr | iPTF16fnl: A Faint and Fast Tidal Disruption Event in an E+A Galaxy |
| title_full_unstemmed | iPTF16fnl: A Faint and Fast Tidal Disruption Event in an E+A Galaxy |
| title_short | iPTF16fnl: A Faint and Fast Tidal Disruption Event in an E+A Galaxy |
| title_sort | iptf16fnl a faint and fast tidal disruption event in an e a galaxy |
| url | http://hdl.handle.net/1721.1/112303 |
| work_keys_str_mv | AT pashamdheerajrangareddy iptf16fnlafaintandfasttidaldisruptioneventinaneagalaxy |