The Formation of Large Galactic Disks: Revival or Survival?

Abstract

Using the deepest and the most complete set of observations of distant galaxies, we investigate how extended disks could have formed. Observations include spatially-resolved kinematics, detailed morphologies and photometry from UV to mid-IR. Six billion years ago, half of the present-day spiral progenitors had anomalous kinematics and morphologies, as well as relatively high gas fractions. We argue that gas-rich major mergers, i.e., fusions between gas-rich disk galaxies of similar mass, can be the likeliest driver for such strong peculiarities. This suggests a new channel of disk formation, e.g. many disks could be reformed after gas-rich mergers. This is found to be in perfect agreement with predictions from the state-of-the-art LCDM semi-empirical models: due to our sensitivity in detecting mergers at all phases, from pairs to relaxed post-mergers, we find a more accurate merger rate. The scenario can be finally confronted to properties of nearby galaxies, including M31 and galaxies showing ultra-faint, gigantic structures in their haloes.

Proceedings of the annual meeting of the French Astronomical Society, 2011, 6 pages, 1 Figure

References in corpus (28)

• The Mass-Metallicity Relation at z~2
• A common mass scale for satellite galaxies of the Milky Way
• Gaseous Galaxy Halos
• Star Formation in Galaxy Mergers with Realistic Models of Stellar Feedback & the Interstellar Medium
• A huge reservoir of ionized gas around the Milky Way: Accounting for the Missing Mass?
• A fitting formula for the merger timescale of galaxies in hierarchical clustering
• The orbital poles of Milky Way satellite galaxies: a rotationally supported disc-of-satellites
• The ghost of a dwarf galaxy: fossils of the hierarchical formation of the nearby spiral galaxy NGC 5907
• Thick disks of edge-on galaxies seen through the Spitzer Survey of Stellar Structure in Galaxies (S4G): Lair of missing baryons?
• IMAGES-III: The evolution of the Near-Infrared Tully-Fisher relation over the last 6 Gyr
• Moving mesh cosmology: characteristics of galaxies and haloes
• Where are the ``Missing'' Galactic Baryons?
• The Radical Consequences of Realistic Satellite Orbits for the Heating and Implied Merger Histories of Galactic Disks
• Systemic Proper Motions of Milky Way Satellites from Stellar Redshifts: the Carina, Fornax, Sculptor and Sextans Dwarf Spheroidals
• IMAGES I. Strong evolution of galaxy kinematics since z=1
• The Stellar Content of Galaxy Halos: A Comparison between LambdaCDM Models and Observations of M31
• Galaxy And Mass Assembly (GAMA): In Search of Milky-Way Magellanic Cloud Analogues
• Does the dwarf galaxy system of the Milky Way originate from Andromeda?
• Galaxy disks do not need to survive in the L-CDM paradigm: the galaxy merger rate out to z~1.5 from morpho-kinematic data
• The Extended Star Formation History of the Andromeda Spheroid at Twenty One Kiloparsecs on the Minor Axis
• Images IV: Strong evolution of the oxygen abundance in gaseous phases of intermediate mass galaxies since z=0.8
• A giant bar induced by a merger event at z=0.4?
• Dwarf spheroidal satellites of the Milky Way from dark matter free tidal dwarf galaxy progenitors: maps of orbits
• A forming, dust enshrouded disk at z=0.43: the first example of a late type disk rebuilt after a major merger?
• Loops formed by tidal tails as fossil records of a major merger
• A decrease of the gas exchanges between galaxies and the IGM, from 12 to 6 billion years ago
• A forming disk at z~0.6: Collapse of a gaseous disk or major merger remnant?
• First detection of a minor merger a z~0.6