J/ApJ/930/L4 ATLAS17jrp light curves and DBSP spectra (Wang+, 2022)
Discovery of ATLAS17jrp as an optical-, X-ray-, and infrared-bright tidal
disruption event in a star-forming galaxy.
Wang Y., Jiang N., Wang T., Zhu J., Dou L., Lin Z., Sun L., Liu H.,
Sheng Z.
<Astrophys. J., 930, L4 (2022)>
=2022ApJ...930L...4W 2022ApJ...930L...4W
ADC_Keywords: Transient; Photometry, infrared; Ultraviolet; Spectra, optical;
X-ray sources
Keywords: Accretion ; Galaxy nuclei
Abstract:
We hereby report the discovery of ATLAS17jrp as an extraordinary tidal
disruption event (TDE) in the star-forming galaxy
SDSS_J162034.99+240726.5 in our recent sample of mid-infrared
outbursts in nearby galaxies. Its optical/UV light curves rise to a
peak luminosity of ∼1.06x1044erg/s in about a month and then decay
as t-5/3 with a roughly constant temperature around 19000K, and the
optical spectra show a blue continuum and very broad Balmer lines with
FWHM∼15000km/s, which gradually narrowed to 1400km/s within 4yr, all
agreeing well with other optical TDEs. A delayed and rapidly rising
X-ray flare with a peak luminosity of ∼1.27x1043erg/s was detected
∼170d after the optical peak. The high MIR luminosity of ATLAS17jrp
(∼2x1043erg/s) has revealed a distinctive dusty environment with a
covering factor as high as ∼0.2, which is comparable to that of a
torus in active galactic nuclei but at least one order of magnitude
higher than normal optical TDEs. Therefore, ATLAS17jrp turns out to be
one of the rare unambiguous TDEs found in star-forming galaxies, and
its high dust-covering factor implies that dust extinction could play
an important role in the absence of optical TDEs in star-forming
galaxies.
Description:
We have collected multiband photometry spanning from UV to MIR,
including data from ATLAS, Swift, and WISE. All light curves are shown
in Figure 1.
ATLAS17jrp was initially discovered by ATLAS on 2017 August 3.
The Swift/UVOT photometry (2017-2018 PI: Blanchard; 2022 PI: Dou)
was measured by the UVOTSOURCE task in the HEASoft package using 5"
apertures, and the AB magnitude was calibrated in the Swift
photometric system.
We reprocessed the event files of Swift/XRT observations; see
Section 2.2.
We obtained the WISE light curves following our previous work (see
Section 2.3 of Jiang+ 2021ApJS..252...32J 2021ApJS..252...32J).
Four spectra were acquired for ATLAS17jrp, including one from
SDSS-DR7, one observed by ePESSTO groups with the ESO-NTT telescope,
and two from our own spectroscopic follow-up campaign of MIRONG
(Wang+ 2022ApJS..258...21W 2022ApJS..258...21W). The ESO spectrum was observed at
UT2017-09-14, near the peak of the optical light curve, while the two
from the MIRONG project (using the Double spectrograph (DBSP) mounted
on the Hale 200 inch telescope at Palomar observatory) were observed
at UT 2019-06-21 and UT 2021-03-17, respectively, both after the
fading out of the UV/optical light curve. All spectra are shown in the
top panel of Figure 2.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
16 20 34.86 +24 07 25.5 ATLAS17jrp = AT 2017gge
----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
swift.dat 30 50 Swift UV/Optical light curve data
(Data behind Figure 1)
atlasc.dat 27 42 ATLAS c band light curve data with host subtraction
(Data behind Figure 1)
atlaso.dat 27 145 ATLAS o band light curve data with host subtraction
(Data behind Figure 1)
wisehost.dat 35 10 WISE W1,W2 band light curve data with host
subtraction (Data behind Figure 1)
wise.dat 35 11 WISE W1,W2 band light curve data without host
subtraction (Data behind Figure 1)
xraybin.dat 28 6 Binned Swift X-ray data
(Data behind Figure 1)
xray.dat 34 18 Individual Swift X-ray data
(Data behind Figure 1)
fig2.dat 40 12317 Our acquired P200/DBSP spectra of ATLAS17jrp
--------------------------------------------------------------------------------
See also:
J/MNRAS/404/1639 : MILES base models & new line index system (Vazdekis+, 2010)
J/ApJ/793/38 : Palomar Transient Factory photometric obs. (Arcavi+, 2014)
J/ApJ/792/30 : NEOWISE magnitudes for near-Earth objects (Mainzer+, 2014)
J/ApJS/219/8 : SFR for WISE + SDSS spectroscopic galaxies (Chang+, 2015)
J/A+A/594/A116 : HI4PI spectra and column density maps (HI4PI team+, 2016)
J/ApJS/252/32 : MIR outbursts in nearby SDSS gal. (MIRONG) I. (Jiang+, 2021)
Byte-by-byte Description of file: swift.dat atlas[co].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 F12.6 d MJD Modified Julian Date
14- 19 F6.3 mag mag [17.3/23] Apparent magnitude in band
21- 25 F5.3 mag e_mag [0.03/9] Uncertainty in mag
27- 30 A4 --- Band Filter band used
--------------------------------------------------------------------------------
Byte-by-byte Description of file: wise*.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.3 d MJD [57604.8/59423.9] Modified Julian Date
11- 16 F6.3 mag W1mag [12.7/18.8] Apparent W1 band magnitude
18- 22 F5.3 mag e_W1mag [0.01/4] Uncertainty in W1mag
24- 29 F6.3 mag W2mag [12.2/17.6] Apparent W2 band magnitude
31- 35 F5.3 mag e_W2mag [0.008/2.4] Uncertainty in W2mag
--------------------------------------------------------------------------------
Byte-by-byte Description of file: xraybin.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- obsid Observation IDs to bin
10- 18 F9.3 d MJD [58087.4/59652] Modified Julian Date
20 A1 --- l_Lum Limit on Lum
21- 28 E8.2 10-7W Lum [1e+40/1.3e+43] Luminosity in 0.3-2keV band
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Byte-by-byte Description of file: xray.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- obsid Observation IDs to bin
7- 15 F9.3 d MJD [58031.1/59652] Modified Julian Date
17- 24 F8.3 s Exp [359.6/3563.7] Exposure time
26 A1 --- l_CRate Limit flag on CRate
27- 34 F8.6 ct/s CRate [0.0002/0.01] Counts rate in 0.3-1keV band
--------------------------------------------------------------------------------
Byte-by-byte Description of file: fig2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "Y/M/D" Date Observation date UT
("2019-06-21" or "2021-03-17")
12- 19 F8.2 0.1nm Wave [2705.4/11913.7] Wavelength; Angstroms
21- 30 E10.3 cW/m2/nm Flux [-1.22e-14/1.82e-14] Flux density;
erg/s/cm2/Angstrom
32- 40 E9.3 cW/m2/nm e_Flux [2.27e-22/1.18e-14] Uncertainty in Flux
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 11-Feb-2025