Galaxy mergers with various mass ratios: properties of remnants

By Frédéric Bournaud, C. Jog, F. Combes. 2005

272 citations recorded by the source corpus.

We study galaxy mergers with various mass ratios using N-body simulations, with an emphasis on the unequal-mass mergers in the relatively unexplored range of mass-ratios 4:1-10:1. Our recent work (Bournaud et al. 2004) shows that the above range of mass ratio results in hybrid systems with spiral-like luminosity profiles but with elliptical-like kinematics, as observed in the data analysis for a sample of mergers by Jog & Chitre (2002). In this paper, we study the merger remnants for mass ratios from 1:1 to 10:1 while systematically covering the parameter space. We obtain the morphological and kinematical properties of the remnants, and also discuss the robustness and the visibility of disks in the merger remnants with a random line-of-sight. We show that the mass ratios 1:1-3:1 give rise to elliptical remnants whereas the mass ratios 4.5:1-10:1 produce hybrid systems with mixed properties. We find that the transition between disk-like and elliptical remnants occurs between a narrow mass range of 4.5:1-3:1. The unequal-mass mergers are more likely to occur than the standard equal-mass mergers studied in the literature so far, and we discuss their implications for the evolution of galaxies.

Subfields: Astronomy and Astrophysics, Computer Vision and Pattern Recognition

View Paper: https://www.semanticscholar.org/paper/f92f0263a0b1657a86c4e66a0ab87a2a4ada43af

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. P. Hopkins
2. L. Hernquist
3. Thomas J. Cox
4. M. Cappellari
5. T. Naab
6. R. Somerville
7. Volker Springel
8. A. Dekel

In Computer Vision and Pattern Recognition

1. P. Hopkins
2. R. Somerville
3. L. Hernquist
4. M. Cappellari
5. M. Sarzi
6. Roger Davies
7. R. McDermid
8. M. Bureau

Citations in the corpus

• MERGERS AND BULGE FORMATION IN ΛCDM: WHICH MERGERS MATTER? (2009, methodology): “…simulations have shown that a sufficiently large number of minor mergers (in a sufficiently short period of time) can do as much to build bulge8 mass as a smaller number of major mergers (Naab & Burkert 2003; Bournaud et al. 2005; Younger et al. 2008a; Cox et al. 2008; Hopkins et al. 2009b).”
• MERGERS IN ΛCDM: UNCERTAINTIES IN THEORETICAL PREDICTIONS AND INTERPRETATIONS OF THE MERGER RATE (2010, result): “We also see a continuum of behavior in between, as has been noted in many numerical studies (Hernquist 1989; Hernquist & Mihos 1995; Naab & Burkert 2003; Cox et al. 2008; Younger et al. 2008; Bournaud et al. 2005; Hopkins et al. 2009a; Johansson et al. 2009b,a).”
• MORPHOLOGICAL QUENCHING OF STAR FORMATION: MAKING EARLY-TYPE GALAXIES RED (2009, background): “Parametric studies in Bournaud & Combes (2002, appendix A) and Bournaud et al. (2005) show that over a certain range, variations of the dissipation parameter β have limited effects on the global evolution of modeled gas disks as a stronger dissipation is compensated by a stronger gravitational…”
• Galaxy formation theory (2010, background): “Numerical simulations (e.g. Bournaud et al. 2005) show that mergers with a mass ratioµ ≡ M2/M1 >∼0.25 are able to destroy any disks in the ingoing galaxies and leave a spheroidal remnant, while mergers with lower mass ratio tend o leave disks in place (although somewhat thickened).”
• Simulations of minor mergers - I. General properties of thick discs (2008, background): “More recently, also the effects of gas, star formation and feedback have been taken into account (Bournaud et al. 2005; Naab et al. 2006; di Matteo et al. 2007; Cox et al. 2008).”
• Integral field spectroscopy with SINFONI of VVDS galaxies I. Galaxy dynamics and mass assembly at 1.2 < z < 1.6 (2009, background): “In large numerical simulations, major and minor mergers are indeed playing an important role (Bournaud et al. 2005), in parallel to continuous gas accretion (Semelin & Combes 2005; Dekel et al. 2009).”
• DISSIPATION AND EXTRA LIGHT IN GALACTIC NUCLEI. IV. EVOLUTION IN THE SCALING RELATIONS OF SPHEROIDS (2008, background): “…of major merger in this context is blurred by a degeneracy betweenth progenitor mass ratio and the orbit (Hernquist 1989; Hernquist & Mihos 1995; Bournaud et al. 2005), but both numerical (Younger et al. 2008) and observational (Dasyra et al. 2006; Woods et al. 2006) studies indicate that…”
• Simulations of binary galaxy mergers and the link with fast rotators, slow rotators, and kinematically distinct cores (2011, methodology): “These observed ETGs could thus be the remnants of a merger between a spiral galaxy and a companion with a mass ratio from 10:1 to 1:1 (see e.g. Bendo & Barnes 2000; Cretton et al. 2001; Naab & Burkert 2003; Bournaud et al. 2005; Naab & Trujillo 2006).”
• A Merger-driven Scenario for Cosmological Disk Galaxy Formation (2005, background): “1 : 2–1 : 3; see Table 2), the Vrot/ 2–2.5 throughout most of the remnant disks substantially exceeds the Vrot/ 1:6 for the comparatively gas-poor mergers reported by Bournaud et al. (2005) for mergers of mass ratio m2 :m1 ¼ 8 : 1 (see their Fig.”
• What drives the growth of black holes (2011, background): “Major mergers clearly occur and trigger AGN activity but there are significant uncertainties in the interpretation of the data; indeed, systems with classical spheroids may have undergone at least one majormerger event at some time during the past (e.g., Bournaud et al., 2005; Hopkins et al., 2010).”
• The influence of gas on the structure of merger remnants (2006, unknown): “We expect that the effect of star formation on the isophotal shape of unequal mass remnants is much weaker (see e.g. Bournaud et al. 2005).”
• SPITZER QUASAR AND ULIRG EVOLUTION STUDY (QUEST). IV. COMPARISON OF 1 Jy ULTRALUMINOUS INFRARED GALAXIES WITH PALOMAR-GREEN QUASARS (2009, background): “This merging process had long been suspected to lead to the formation of an elliptical galaxy (e.g., Toomre & Toomre 1972) and subsequent numerical simulations have lent support to this idea (e.g., Barnes 1989; Kormendy & Sanders 1992; Springel et al. 2005; Bournaud et al. 2005; Naab et al. 2006).”
• An analytic model of angular momentum transport by gravitational torques: from galaxies to massive black holes (2010, background): “The “pile up” of material in these shocks manifests itself observationally as dust lanes and enhanced star formation in the leading edge of spiral arms (Roberts et al. 1979; Athanassoula 1992b; Wada 1994; Bournaud et al. 2005).”
• The Kinematic Structure of Merger Remnants (2006, background): “…that other work has also shown that multiple merger remnants can remain on the fundamental plane (Capelato et al. 1995; Nipoti et al. 2003; González-Garćıa & van Albada 2003; Boylan-Kolchin et al. 2006; Robertson et al. 2006a) and may have R1/4 surface brightness profiles (Bournaud et al. 2005).”
• A DEEP HUBBLE SPACE TELESCOPE H-BAND IMAGING SURVEY OF MASSIVE GAS-RICH MERGERS. II. THE QUEST QSOs (2006, background): “However, one should remember that the three lowest luminosity PG QSOs in our sample also harbor a significant disk component that is difficult to explain in the context of major mergers (e.g., Naab & Burkert 2001, 2003; Bournaud et al. 2004, 2005).”