| Title: |
Gravitational Wave Measurement of the Mbh-Mbulge Intrinsic Scatter at High Redshift |
| Authors: |
Matt, Cayenne; Gültekin, Kayhan; Agazie, Gabriella; Agarwal, Nikita; Anumarlapudi, Akash; Archibald, Anne M.; Arzoumanian, Zaven; Baier, Jeremy G.; Baker, Paul T.; Bécsy, Bence; Blecha, Laura; Brazier, Adam; Brook, Paul R.; Burke-Spolaor, Sarah; Burnette, Rand; Case, Robin; Casey-Clyde, J. Andrew; Charisi, Maria; Chatterjee, Shami; Cohen, Tyler; Cordes, James M.; Cornish, Neil J.; Crawford, Fronefield; Cromartie, H. Thankful; Crowter, Kathryn; DeCesar, Megan E.; Demorest, Paul B.; Deng, Heling; Dey, Lankeswar; Dolch, Timothy; Doskoch, Graham M.; Ferrara, Elizabeth C.; Fiore, William; Fonseca, Emmanuel; Freedman, Gabriel E.; Gardiner, Emiko C.; Garver-Daniels, Nate; Gentile, Peter A.; Gersbach, Kyle A.; Glaser, Joseph; Good, Deborah C.; Harris, C. J.; Hazboun, Jeffrey S.; Jennings, Ross J.; Johnson, Aaron D.; Jones, Megan L.; Kaplan, David L.; Sreekumar, Anala Kavumkandathil; Kelley, Luke Zoltan; Kerr, Matthew; Key, Joey S.; Laal, Nima; Lam, Michael T.; Lamb, William G.; Larsen, Bjorn; Lazio, T. Joseph W.; Lewandowska, Natalia; Liu, Tingting; Lorimer, Duncan R.; Luo, Jing; Lynch, Ryan S.; Ma, Chung-Pei; Madison, Dustin R.; Martsen, Ashley; McEwen, Alexander; McKee, James W.; McLaughlin, Maura A.; McMann, Natasha; Meyers, Bradley W.; Meyers, Patrick M.; Mingarelli, Chiara M. F.; Mitridate, Andrea; Ng, Cherry; Nice, David J.; Nichols, Shania; Ocker, Stella Koch; Olum, Ken D.; Pennucci, Timothy T.; Perera, Benetge B. P.; Petrov, Polina; Pol, Nihan S.; Radovan, Henri A.; Ransom, Scott M.; Ray, Paul S.; Romano, Joseph D.; Runnoe, Jessie C.; Saffer, Alexander; Sardesai, Shashwat C.; Schmiedekamp, Ann; Schmiedekamp, Carl; Schmitz, Kai; Shapiro-Albert, Brent J.; Siemens, Xavier; Simon, Joseph; Fiscella, Sophia V. Sosa; Stairs, Ingrid H.; Stinebring, Daniel R.; Stovall, Kevin; Susobhanan, Abhimanyu; Swiggum, Joseph K.; Taylor, Jacob; Taylor, Stephen R.; Thompson, Mercedes S.; Turner, Jacob E.; Vallisneri, Michele; van Haasteren, Rutger; Vigeland, Sarah J.; Wahl, Haley M.; Wilson, Kevin P.; Witt, Caitlin A.; Wright, David; Young, Olivia |
| Publication Year: |
2026 |
| Collection: |
ArXiv.org (Cornell University Library) |
| Subject Terms: |
High Energy Astrophysical Phenomena; Cosmology and Nongalactic Astrophysics; Astrophysics of Galaxies |
| Description: |
The observed GWB spectrum is higher in amplitude than model predictions by a factor of 2-3. Using a semi-analytic model, we evaluate the effect of a high-scatter supermassive black hole (SMBH) scaling relation (Mbh-Mbulge) on models of the nanoHertz gravitational wave background (GWB). By implementing an intrinsic scatter of the Mbh-Mbulge relation, which is larger at higher redshift, but matches local observations, we find that the amplitude of GWB models increases to be consistent with the low-frequency end of the GWB spectrum. This amplitude increase is not uniform across frequencies, a strongly evolving scatter preferentially increases the number density of the most massive SMBHs which, in the GWB spectrum, minimizes the strength of the low-frequency turnover. Our models with positively evolving intrinsic scatter can reproduce the electromagnetically observed overmassive SMBHs at 4 < z < 6 without changing the Mbh-Mbulge normalization though we find that including moderate normalization evolution improves fits to the GWB data. We conclude that the Mbh-Mbulge relation which best describes the available GWB and electromagnetic data sets has intrinsic scatter which evolves as epsilon(z) = epsilon_0 + (0.56 +/- 0.4) log10(1 + z) and normalization which evolves as alpha(z) = alpha_0 (1 + z)^(0.84 +/- 0.35). The results of this work imply that the Mbh-Mbulge relation we see today is not universal throughout cosmic time and that a diversity of seeding models and growth mechanisms may be at play in the early stages of SMBH-galaxy evolution. ; Submitted to AAS journals |
| Document Type: |
text |
| Language: |
unknown |
| Relation: |
http://arxiv.org/abs/2603.11167 |
| Availability: |
http://arxiv.org/abs/2603.11167 |
| Accession Number: |
edsbas.D996782A |
| Database: |
BASE |