TY - JOUR
T1 - Evidence for the Preferential Disruption of Moderately Massive Stars by Supermassive Black Holes
AU - Mockler, Brenna
AU - Twum, Angela A.
AU - Auchettl, Katie
AU - Dodd, Sierra
AU - French, K. D.
AU - Law-Smith, Jamie A.P.
AU - Ramirez-Ruiz, Enrico
N1 - Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society..
PY - 2022/1/10
Y1 - 2022/1/10
N2 - Tidal disruption events (TDEs) provide a unique opportunity to probe the stellar populations around supermassive black holes (SMBHs). By combining light-curve modeling with spectral line information and knowledge about the stellar populations in the host galaxies, we are able to constrain the properties of the disrupted star for three TDEs. The TDEs in our sample have UV spectra, and measurements of the UV N iii to C iii line ratios enabled estimates of the nitrogen-to-carbon abundance ratios for these events. We show that the measured nitrogen line widths are consistent with originating from the disrupted stellar material dispersed by the central SMBH. We find that these nitrogen-to-carbon abundance ratios necessitate the disruption of moderately massive stars (⪆1-2 M o˙). We determine that these moderately massive disruptions are overrepresented by a factor of ⪆102 when compared to the overall stellar population of the post-starburst galaxy hosts. This implies that SMBHs are preferentially disrupting higher mass stars, possibly due to ongoing top-heavy star formation in nuclear star clusters or to dynamical mechanisms that preferentially transport higher mass stars to their tidal radii.
AB - Tidal disruption events (TDEs) provide a unique opportunity to probe the stellar populations around supermassive black holes (SMBHs). By combining light-curve modeling with spectral line information and knowledge about the stellar populations in the host galaxies, we are able to constrain the properties of the disrupted star for three TDEs. The TDEs in our sample have UV spectra, and measurements of the UV N iii to C iii line ratios enabled estimates of the nitrogen-to-carbon abundance ratios for these events. We show that the measured nitrogen line widths are consistent with originating from the disrupted stellar material dispersed by the central SMBH. We find that these nitrogen-to-carbon abundance ratios necessitate the disruption of moderately massive stars (⪆1-2 M o˙). We determine that these moderately massive disruptions are overrepresented by a factor of ⪆102 when compared to the overall stellar population of the post-starburst galaxy hosts. This implies that SMBHs are preferentially disrupting higher mass stars, possibly due to ongoing top-heavy star formation in nuclear star clusters or to dynamical mechanisms that preferentially transport higher mass stars to their tidal radii.
UR - http://www.scopus.com/inward/record.url?scp=85123532195&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85123532195&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/ac35d5
DO - 10.3847/1538-4357/ac35d5
M3 - Article
AN - SCOPUS:85123532195
SN - 0004-637X
VL - 924
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 70
ER -