Joint Modeling of GD-1 and C-19 as Old Streams

@article{carlberg2026joint,
  title = {{Joint Modeling of GD-1 and C-19 as Old Streams}},
  author = {Raymond G. Carlberg and Ting S. Li and Emma Jarvis and Nasser Mohammed and Joan Najita and Arjun Dey and Sergey E. Koposov and Jakob Piafsky and Leandro Beraldo e Silva and Constance M. Rockosi and J. Aguilar and S. Ahlen and D. Bianchi and D. Brooks and T. Claybaugh and A. de la Macorra and Biprateep Dey and P. Doel and A. Font-Ribera and J. E. Forero-Romero and Satya Gontcho A Gontcho and G. Gutierrez and R. Joyce and S. Juneau and A. Kremin and O. Lahav and M. Landriau and L. Le Guillou and A. Meisner and R. Miquel and W. J. Percival and C. Poppett and F. Prada and I. Pérez-Ràfols and G. Rossi and E. Sanchez and D. Schlegel and J. Silber and G. Tarlé and B. A. Weaver and R. Zhou and H. Zou},
  journal = {The Astrophysical Journal},
  year = {2026},
  month = oct,
  doi = {10.3847/1538-4357/aea793},
  url = {https://iopscience.iop.org/article/10.3847/1538-4357/aea793},
  note = {CC BY 4.0},
}

TY  - JOUR
TI  - Joint Modeling of GD-1 and C-19 as Old Streams
AU  - Raymond G. Carlberg
AU  - Ting S. Li
AU  - Emma Jarvis
AU  - Nasser Mohammed
AU  - Joan Najita
AU  - Arjun Dey
AU  - Sergey E. Koposov
AU  - Jakob Piafsky
AU  - Leandro Beraldo e Silva
AU  - Constance M. Rockosi
AU  - J. Aguilar
AU  - S. Ahlen
AU  - D. Bianchi
AU  - D. Brooks
AU  - T. Claybaugh
AU  - A. de la Macorra
AU  - Biprateep Dey
AU  - P. Doel
AU  - A. Font-Ribera
AU  - J. E. Forero-Romero
AU  - Satya Gontcho A Gontcho
AU  - G. Gutierrez
AU  - R. Joyce
AU  - S. Juneau
AU  - A. Kremin
AU  - O. Lahav
AU  - M. Landriau
AU  - L. Le Guillou
AU  - A. Meisner
AU  - R. Miquel
AU  - W. J. Percival
AU  - C. Poppett
AU  - F. Prada
AU  - I. Pérez-Ràfols
AU  - G. Rossi
AU  - E. Sanchez
AU  - D. Schlegel
AU  - J. Silber
AU  - G. Tarlé
AU  - B. A. Weaver
AU  - R. Zhou
AU  - H. Zou
PY  - 2026
DA  - 2026/10/12
JO  - The Astrophysical Journal
DO  - 10.3847/1538-4357/aea793
UR  - https://iopscience.iop.org/article/10.3847/1538-4357/aea793
AB  - DESI observational data for the GD-1 and C-19 streams are compared to stream simulations in an evolving multihalo potential of a Milky Way–like galaxy based on a cosmological Milky Way–like simulation. The number of subhalos decreases with time, and the subhalo-stream encounter velocities rise as the galaxy and its disk build up their mass. The streams develop from star clusters inserted at ≃1 Gyr after the Big Bang and evolved for 13 Gyr to their current orbital positions. The measured velocity widths of the streams are compared to the matched simulations. Streams in a cold dark matter (CDM) subhalo population provide the best match to the velocity width, on average, with considerable scatter. Streams younger than ≃12 Gyr in CDM subhalos are insufficiently hot. Streams in the same potentials but with populations of warm dark matter (WDM) 5.5 keV subhalos are not, on average, heated to the observed velocity widths, although some of the realizations do reach the observed levels. The stream density power spectrum measured along the length of the DESI GD-1 sample agrees with the CDM stream simulations, with 1.3–2.3 times more power than WDM 7 and 5.5 keV simulations. The simulations show that modeling specific streams from the time of the formation of their progenitor clusters is both feasible and necessary to reproduce their stream-averaged kinematic properties.
SN  - 0004-637X
SN  - 1538-4357
ER  -