Hostname: page-component-76fb5796d-r6qrq Total loading time: 0 Render date: 2024-04-29T16:03:18.909Z Has data issue: false hasContentIssue false
  • English
  • Français

Helium rich stars produce the UV upturn

Published online by Cambridge University Press:  10 June 2020

R. De Propris ,
S. Ali ,
M. N. Bremer  and
S. Phillipps
R. De Propris
Affiliation:
FINCA, University of Turku, 20014, Finland email: rodepr@utu.fi
S. Ali
Affiliation:
H. H. Wills Physics Laboratory, University of Bristol, United Kingdom emails: s.ali@bristol.ac.uk, m.bremer@bristol.ac.uk, s.phillipps@bristol.ac.uk
M. N. Bremer
Affiliation:
H. H. Wills Physics Laboratory, University of Bristol, United Kingdom emails: s.ali@bristol.ac.uk, m.bremer@bristol.ac.uk, s.phillipps@bristol.ac.uk
S. Phillipps
Affiliation:
H. H. Wills Physics Laboratory, University of Bristol, United Kingdom emails: s.ali@bristol.ac.uk, m.bremer@bristol.ac.uk, s.phillipps@bristol.ac.uk
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We measure the evolution of the UV upturn color for galaxies on the red sequence in clusters at 0 < z < 0.7 and to luminosity levels L ∼ L*. We show that the UV upturn color does not change until at least z = 0.55 but becomes significantly redder at z = 0.7. This is the first detection of evolution in the UV upturn. Our observations are inconsistent with all models proposed for its origin except the presence of a population of helium enriched stars, with helium abundances above 42 % and formed at z > 4.

Keywords

ultraviolet: galaxiesgalaxies: stellar contentgalaxies: elliptical and lenticularcDstars: horizontal-branch
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 15 , Symposium S341: Challenges in Panchromatic Modelling with Next Generation Facilities , November 2019 , pp. 264 - 265
Copyright
© International Astronomical Union 2020

References

Ali, S., Bremer, M., Phillipps, S., & De Propris, R. 2018a, MNRAS, 476, 1010CrossRefGoogle Scholar
Ali, S., Bremer, M., Phillipps, S., & De Propris, R. 2018b, MNRAS, 478, 541CrossRefGoogle Scholar
Ali, S., Bremer, M., Phillipps, S., & De Propris, R. 2018c, MNRAS, 480, 2236CrossRefGoogle Scholar
Bastian, N. & Lardo, C. 2018, ARA&A, 56, 83CrossRefGoogle Scholar
Boissier, S., Cucciati, O., Boselli, A., Mei, S., & Ferrarese, L. 2018, A&A, 611, A42Google Scholar
Chung, C., Yook, S.-J., & Lee, Y.-W. 2017, ApJ, 842, A91CrossRefGoogle Scholar
Greggio, L. & Renzini, A. 1990, ApJ, 364, 35CrossRefGoogle Scholar
Han, Z., Podsiadlowski, P., & Lynas-Gray, A. E. 2007, MNRAS, 380, 109810.1111/j.1365-2966.2007.12151.xCrossRefGoogle Scholar
Park, J.-H. & Lee, Y.-W. 1997, ApJ, 476, 28CrossRefGoogle Scholar
Yi, S. K., Demarque, P., & Oemler, A. 1998, ApJ, 492, 480CrossRefGoogle Scholar
Yi, S. K. 2008, Stellar Populations - Planning for the Next Decade, IAU Symposium, 262, 147Google Scholar
Yi, S. K. 2010, Hot Subdwarf Stars and Related Objects, ASP Conference Series, 392, 3Google Scholar