Observations of Malin 1, a nearby galaxy and a perfect prototype of the "giant galaxies with low surface brightness," have allowed scientists from an international team including a researcher from the Astrophysics Laboratory-Service AIM CEA-IRFU to make an unexpected discovery that challenges the assumptions about galaxy formation process of this type. It suggests that the giant disk in Malin-1, the largest known in the universe, is not the consequence of a collision but is in place for several billion years, and that stars are formed there in a modest but steady rate over the long-term. Because of their diffuse appearance and their very low gloss, these massive galaxies are difficult to observe and remain unknown today. They could be a significant fraction of the galaxies in the universe, as similar objects as Malin 1 may have escaped our vigilance.
The paper, published in Astronomy and Astrophysics, presents for the first time images of Malin 1 obtained six different wavelengths - from ultraviolet through GUViCS1 project in optical and near infrared through NGVS1 project with the camera MegaCam Canada France Hawaii Telescope, CFHT developed at the CEA . Originally planned to study the Virgo cluster, these large observation campaigns also allow working on other objects in the background of this cluster, as is the case in this study.
For more information : see the French version
Contact : Jean-Charles CUILLANDRE
"The properties of the Malin 1 galaxy giant disk: A panchromatic view from the NGVS and GUViCS surveys"
S. Boissier et al., published in Astronomy & Astrophysics, 2016, A&A, 593, A126 septembre 2016, DOI 10.1051/0004-6361/201629226.
For a numerical version https://arxiv.org/abs/1610.00918v1