Discovery and follow-up of ASASSN-19dj: An X-ray and UV luminous TDE in an extreme post-starburst galaxy

Jason T. Hinkle; T. W.S. Holoien; K. Auchettl; B. J. Shappee; J. M.M. Neustadt; A. V. Payne; J. S. Brown; C. S. Kochanek; K. Z. Stanek; M. J. Graham; M. A. Tucker; A. Do; J. P. Anderson; S. Bose; P. Chen; D. A. Coulter; G. Dimitriadis; Subo Dong; R. J. Foley; M. E. Huber; T. Hung; C. D. Kilpatrick; G. Pignata; A. L. Piro; C. Rojas-Bravo; M. R. Siebert; B. Stalder; Todd A. Thompson; J. L. Tonry; P. J. Vallely; J. P. Wisniewski

doi:10.1093/mnras/staa3170

Discovery and follow-up of ASASSN-19dj: An X-ray and UV luminous TDE in an extreme post-starburst galaxy

Jason T. Hinkle^*, T. W.S. Holoien, K. Auchettl, B. J. Shappee, J. M.M. Neustadt, A. V. Payne, J. S. Brown, C. S. Kochanek, K. Z. Stanek, M. J. Graham, M. A. Tucker, A. Do, J. P. Anderson, S. Bose, P. Chen, D. A. Coulter, G. Dimitriadis, Subo Dong, R. J. Foley, M. E. HuberT. Hung, C. D. Kilpatrick, G. Pignata, A. L. Piro, C. Rojas-Bravo, M. R. Siebert, B. Stalder, Todd A. Thompson, J. L. Tonry, P. J. Vallely, J. P. Wisniewski

^*Corresponding author for this work

CIERA - Center for Interdisciplinary Exploration and Research in Astrophysics

Research output: Contribution to journal › Article › peer-review

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Abstract

We present observations of ASASSN-19dj, a nearby tidal disruption event (TDE) discovered in the post-starburst galaxy KUG 0810+227 by the All-Sky Automated Survey for Supernovae (ASAS-SN) at a distance of d ≃ 98 Mpc. We observed ASASSN-19dj from -21 to 392 d relative to peak ultraviolet (UV)/optical emission using high-cadence, multiwavelength spectroscopy and photometry. From the ASAS-SN g-band data, we determine that the TDE began to brighten on 2019 February 6.8 and for the first 16 d the rise was consistent with a flux α2 power law. ASASSN-19dj peaked in the UV/optical on 2019 March 6.5 (MJD = 58548.5) at a bolometric luminosity of L = (6.2 ± 0.2) × 1044 erg s-1. Initially remaining roughly constant in X-rays and slowly fading in the UV/optical, the X-ray flux increased by over an order of magnitude ∼225 d after peak, resulting from the expansion of the X-ray emitting region. The late-time X-ray emission is well fitted by a blackbody with an effective radius of ∼1 × 1012 cm and a temperature of ∼6 × 105 K. The X-ray hardness ratio becomes softer after brightening and then returns to a harder state as the X-rays fade. Analysis of Catalina Real-Time Transient Survey images reveals a nuclear outburst roughly 14.5 yr earlier with a smooth decline and a luminosity of LV ≥ 1.4 × 1043 erg s-1, although the nature of the flare is unknown. ASASSN-19dj occurred in the most extreme post-starburst galaxy yet to host a TDE, with Lick HδA = 7.67 ± 0.17 Å.

Original language	English (US)
Pages (from-to)	1673-1696
Number of pages	24
Journal	Monthly Notices of the Royal Astronomical Society
Volume	500
Issue number	2
DOIs	https://doi.org/10.1093/mnras/staa3170
State	Published - Jan 1 2021

Keywords

Accretion
Accretion discs
Black hole physics
Galaxies: nuclei

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

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10.1093/mnras/staa3170

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Hinkle, J. T., Holoien, T. W. S., Auchettl, K., Shappee, B. J., Neustadt, J. M. M., Payne, A. V., Brown, J. S., Kochanek, C. S., Stanek, K. Z., Graham, M. J., Tucker, M. A., Do, A., Anderson, J. P., Bose, S., Chen, P., Coulter, D. A., Dimitriadis, G., Dong, S., Foley, R. J., ... Wisniewski, J. P. (2021). Discovery and follow-up of ASASSN-19dj: An X-ray and UV luminous TDE in an extreme post-starburst galaxy. Monthly Notices of the Royal Astronomical Society, 500(2), 1673-1696. https://doi.org/10.1093/mnras/staa3170

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title = "Discovery and follow-up of ASASSN-19dj: An X-ray and UV luminous TDE in an extreme post-starburst galaxy",

abstract = "We present observations of ASASSN-19dj, a nearby tidal disruption event (TDE) discovered in the post-starburst galaxy KUG 0810+227 by the All-Sky Automated Survey for Supernovae (ASAS-SN) at a distance of d ≃ 98 Mpc. We observed ASASSN-19dj from -21 to 392 d relative to peak ultraviolet (UV)/optical emission using high-cadence, multiwavelength spectroscopy and photometry. From the ASAS-SN g-band data, we determine that the TDE began to brighten on 2019 February 6.8 and for the first 16 d the rise was consistent with a flux α2 power law. ASASSN-19dj peaked in the UV/optical on 2019 March 6.5 (MJD = 58548.5) at a bolometric luminosity of L = (6.2 ± 0.2) × 1044 erg s-1. Initially remaining roughly constant in X-rays and slowly fading in the UV/optical, the X-ray flux increased by over an order of magnitude ∼225 d after peak, resulting from the expansion of the X-ray emitting region. The late-time X-ray emission is well fitted by a blackbody with an effective radius of ∼1 × 1012 cm and a temperature of ∼6 × 105 K. The X-ray hardness ratio becomes softer after brightening and then returns to a harder state as the X-rays fade. Analysis of Catalina Real-Time Transient Survey images reveals a nuclear outburst roughly 14.5 yr earlier with a smooth decline and a luminosity of LV ≥ 1.4 × 1043 erg s-1, although the nature of the flare is unknown. ASASSN-19dj occurred in the most extreme post-starburst galaxy yet to host a TDE, with Lick HδA = 7.67 ± 0.17 {\AA}.",

keywords = "Accretion, Accretion discs, Black hole physics, Galaxies: nuclei",

author = "Hinkle, {Jason T.} and Holoien, {T. W.S.} and K. Auchettl and Shappee, {B. J.} and Neustadt, {J. M.M.} and Payne, {A. V.} and Brown, {J. S.} and Kochanek, {C. S.} and Stanek, {K. Z.} and Graham, {M. J.} and Tucker, {M. A.} and A. Do and Anderson, {J. P.} and S. Bose and P. Chen and Coulter, {D. A.} and G. Dimitriadis and Subo Dong and Foley, {R. J.} and Huber, {M. E.} and T. Hung and Kilpatrick, {C. D.} and G. Pignata and Piro, {A. L.} and C. Rojas-Bravo and Siebert, {M. R.} and B. Stalder and Thompson, {Todd A.} and Tonry, {J. L.} and Vallely, {P. J.} and Wisniewski, {J. P.}",

note = "Publisher Copyright: {\textcopyright} 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.",

year = "2021",

month = jan,

day = "1",

doi = "10.1093/mnras/staa3170",

language = "English (US)",

volume = "500",

pages = "1673--1696",

journal = "Monthly Notices of the Royal Astronomical Society",

issn = "0035-8711",

publisher = "Oxford University Press",

number = "2",

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Hinkle, JT, Holoien, TWS, Auchettl, K, Shappee, BJ, Neustadt, JMM, Payne, AV, Brown, JS, Kochanek, CS, Stanek, KZ, Graham, MJ, Tucker, MA, Do, A, Anderson, JP, Bose, S, Chen, P, Coulter, DA, Dimitriadis, G, Dong, S, Foley, RJ, Huber, ME, Hung, T, Kilpatrick, CD, Pignata, G, Piro, AL, Rojas-Bravo, C, Siebert, MR, Stalder, B, Thompson, TA, Tonry, JL, Vallely, PJ & Wisniewski, JP 2021, 'Discovery and follow-up of ASASSN-19dj: An X-ray and UV luminous TDE in an extreme post-starburst galaxy', Monthly Notices of the Royal Astronomical Society, vol. 500, no. 2, pp. 1673-1696. https://doi.org/10.1093/mnras/staa3170

TY - JOUR

T1 - Discovery and follow-up of ASASSN-19dj

T2 - An X-ray and UV luminous TDE in an extreme post-starburst galaxy

AU - Hinkle, Jason T.

AU - Holoien, T. W.S.

AU - Auchettl, K.

AU - Shappee, B. J.

AU - Neustadt, J. M.M.

AU - Payne, A. V.

AU - Brown, J. S.

AU - Kochanek, C. S.

AU - Stanek, K. Z.

AU - Graham, M. J.

AU - Tucker, M. A.

AU - Do, A.

AU - Anderson, J. P.

AU - Bose, S.

AU - Chen, P.

AU - Coulter, D. A.

AU - Dimitriadis, G.

AU - Dong, Subo

AU - Foley, R. J.

AU - Huber, M. E.

AU - Hung, T.

AU - Kilpatrick, C. D.

AU - Pignata, G.

AU - Piro, A. L.

AU - Rojas-Bravo, C.

AU - Siebert, M. R.

AU - Stalder, B.

AU - Thompson, Todd A.

AU - Tonry, J. L.

AU - Vallely, P. J.

AU - Wisniewski, J. P.

PY - 2021/1/1

Y1 - 2021/1/1

N2 - We present observations of ASASSN-19dj, a nearby tidal disruption event (TDE) discovered in the post-starburst galaxy KUG 0810+227 by the All-Sky Automated Survey for Supernovae (ASAS-SN) at a distance of d ≃ 98 Mpc. We observed ASASSN-19dj from -21 to 392 d relative to peak ultraviolet (UV)/optical emission using high-cadence, multiwavelength spectroscopy and photometry. From the ASAS-SN g-band data, we determine that the TDE began to brighten on 2019 February 6.8 and for the first 16 d the rise was consistent with a flux α2 power law. ASASSN-19dj peaked in the UV/optical on 2019 March 6.5 (MJD = 58548.5) at a bolometric luminosity of L = (6.2 ± 0.2) × 1044 erg s-1. Initially remaining roughly constant in X-rays and slowly fading in the UV/optical, the X-ray flux increased by over an order of magnitude ∼225 d after peak, resulting from the expansion of the X-ray emitting region. The late-time X-ray emission is well fitted by a blackbody with an effective radius of ∼1 × 1012 cm and a temperature of ∼6 × 105 K. The X-ray hardness ratio becomes softer after brightening and then returns to a harder state as the X-rays fade. Analysis of Catalina Real-Time Transient Survey images reveals a nuclear outburst roughly 14.5 yr earlier with a smooth decline and a luminosity of LV ≥ 1.4 × 1043 erg s-1, although the nature of the flare is unknown. ASASSN-19dj occurred in the most extreme post-starburst galaxy yet to host a TDE, with Lick HδA = 7.67 ± 0.17 Å.

AB - We present observations of ASASSN-19dj, a nearby tidal disruption event (TDE) discovered in the post-starburst galaxy KUG 0810+227 by the All-Sky Automated Survey for Supernovae (ASAS-SN) at a distance of d ≃ 98 Mpc. We observed ASASSN-19dj from -21 to 392 d relative to peak ultraviolet (UV)/optical emission using high-cadence, multiwavelength spectroscopy and photometry. From the ASAS-SN g-band data, we determine that the TDE began to brighten on 2019 February 6.8 and for the first 16 d the rise was consistent with a flux α2 power law. ASASSN-19dj peaked in the UV/optical on 2019 March 6.5 (MJD = 58548.5) at a bolometric luminosity of L = (6.2 ± 0.2) × 1044 erg s-1. Initially remaining roughly constant in X-rays and slowly fading in the UV/optical, the X-ray flux increased by over an order of magnitude ∼225 d after peak, resulting from the expansion of the X-ray emitting region. The late-time X-ray emission is well fitted by a blackbody with an effective radius of ∼1 × 1012 cm and a temperature of ∼6 × 105 K. The X-ray hardness ratio becomes softer after brightening and then returns to a harder state as the X-rays fade. Analysis of Catalina Real-Time Transient Survey images reveals a nuclear outburst roughly 14.5 yr earlier with a smooth decline and a luminosity of LV ≥ 1.4 × 1043 erg s-1, although the nature of the flare is unknown. ASASSN-19dj occurred in the most extreme post-starburst galaxy yet to host a TDE, with Lick HδA = 7.67 ± 0.17 Å.

KW - Accretion

KW - Accretion discs

KW - Black hole physics

KW - Galaxies: nuclei

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U2 - 10.1093/mnras/staa3170

DO - 10.1093/mnras/staa3170

M3 - Article

AN - SCOPUS:85096938901

SN - 0035-8711

VL - 500

SP - 1673

EP - 1696

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

IS - 2

ER -

Discovery and follow-up of ASASSN-19dj: An X-ray and UV luminous TDE in an extreme post-starburst galaxy

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