Kinemetry of SINS High-Redshift Star-Forming Galaxies: Distinguishing Rotating Disks from Major Mergers

By K. Shapiro, R. Genzel, N. F. Förster Schreiber, L. Tacconi, N. Bouché, G. Cresci, R. Davies, F. Eisenhauer, Peter H. Johansson, D. Krajnovi'c and 16 more. 2008

223 citations recorded by the source corpus.

We present a simple set of kinematic criteria that can distinguish between galaxies dominated by ordered rotational motion and those involved in major merger events. Our criteria are based on the dynamics of the warm ionized gas (as traced by Hα) within galaxies, making this analysis accessible to high-redshift systems, whose kinematics are primarily traceable through emission features. Using the method of kinemetry (developed by Krajnović and coworkers), we quantify asymmetries in both the velocity and velocity dispersion maps of the warm gas, and the resulting criteria enable us to empirically differentiate between nonmerging and merging systems at high redshift. We apply these criteria to 11 of our best-studied rest-frame UV/optical-selected z ∼ 2 galaxies for which we have near-infrared integral-field spectroscopic data from SINFONI on the VLT. Of these 11 systems, we find that >50% have kinematics consistent with a single rotating disk interpretation, while the remaining systems are more likely undergoing major mergers. This result, combined with the short formation timescales of these systems, provides evidence that rapid, smooth accretion of gas plays a significant role in galaxy formation at high redshift.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/4b1f9438e99b208e8b5fef9461a25ff22a6719df

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. R. Dav'e
4. A. Dekel
5. R. Somerville
6. T. Naab
7. Volker Springel
8. Thomas J. Cox

In Instrumentation

1. P. Hopkins
2. L. Hernquist
3. A. Dekel
4. R. Dav'e
5. R. Somerville
6. P. V. van Dokkum
7. C. Conroy
8. T. Naab

Citations in the corpus

• THE ROLE OF COLD FLOWS IN THE ASSEMBLY OF GALAXY DISKS (2008, background): “…al. 1999; Labbé et al. 2003; Ravindranath et al. 2004; Ferguson et al. 2004; Trujillo & Aguerri 2004; Barden et al. 2005; Sargent et al. 2007; Melbourne et al. 2007; Kanwar et al. 2008), or even by z = 2 (Förster Schreiber et al. 2006; Shapiro et al. 2008; Genzel et al. 2008; Dekel et al. 2008).”
• EVIDENCE FOR A CLUMPY, ROTATING GAS DISK IN A SUBMILLIMETER GALAXY AT z = 4 (2012, background): “According to Shapiro et al. (2008), the best way to distinguish between CMA and a gas–rich merger model is through observations of the gas dynamics and distribution.”
• OVERVIEW OF THE SDSS-IV MaNGA SURVEY: MAPPING NEARBY GALAXIES AT APACHE POINT OBSERVATORY (2014, background): “…the surprising diversity of kinematic structure, including large rotating disks, compact dispersiondominated objects, and major mergers (e.g., Shapiro et al. 2008; Förster Schreiber et al. 2009; Law et al. 2009), not to mention evidence for winds and outflows (e.g., Steidel et al. 2010;…”
• The KMOS Redshift One Spectroscopic Survey (KROSS):dynamical properties, gas and dark matter fractions of typical z~1 star-forming galaxies (2016, unknown): “…to resolve relatively small samples of up to 100 galaxies on a time consuming one-by-one basis (e.g. Smith et al. 2004; Genzel et al. 2006, 2008; Shapiro et al. 2008; Förster Schreiber et al. 2009 [Spectroscopic Imaging survey in the Near-infrared with SINFONI, (SINS)]; Gnerucci et al. 2011;…”
• The SINS/zC-SINF Survey of z ∼ 2 Galaxy Kinematics: SINFONI Adaptive Optics–assisted Data and Kiloparsec-scale Emission-line Properties (2018, methodology): “• K20-ID7 — Based on seeing-limited SINFONI data, this source had been classified as major merger mainly because of the non-axisymmetry of the velocity dispersion map (Shapiro et al. 2008).”
• VLT/VIMOS integral field spectroscopy of luminous and ultraluminous infrared galaxies: 2D kinematic properties (2013, unknown): “…(e.g., Puech et al. 2007; Epinat et al. 2009), ii) to distinguish betwe n relaxed virialized systems and merger events (e.g., Floreset al. 2006; Shapiro et al. 2008; Bellocchi et al. 2012), iii) to detect and characterize radial motions associated with feedback me ha- nisms, like outflows…”
• THE SINS SURVEY: MODELING THE DYNAMICS OF z ∼ 2 GALAXIES AND THE HIGH-z TULLY–FISHER RELATION (2009, methodology): “…results showing that smooth gas accretion from the halo is required to reproduce the observed properties of a large fraction of the z ∼ 2 galaxies (see e.g. Förster Schreiber et al. 2006; Genzel et al. 2006, 2008; Shapiro et al. 2008; Noeske et al. 2007; Elbaz et al. 2007; Daddi et al. 2007b).”
• SHORT-LIVED STAR-FORMING GIANT CLUMPS IN COSMOLOGICAL SIMULATIONS OF z ≈ 2 DISKS (2010, background): “The disk shows regular rotation (Figure 3(e)), indicative of its quiet merger history (Shapiro et al. 2008).”
• The effects of gas on morphological transformation in mergers: implications for bulge and disc demographics (2009, background): “…et al. 2006; Atkinson et al. 2007; Puech et al. 2007b; Neichel et al. 2008; Yang et al. 2008) especially approaching z ∼ 2 (Bouché et al. 2007; Shapiro et al. 2008; van Starkenburg et al. 2008), and agrees well with the structure of simulated discs undergoing rapid simultaneous accretion…”
• THE IMPACT OF COLD GAS ACCRETION ABOVE A MASS FLOOR ON GALAXY SCALING RELATIONS (2009, background): “…properties, our detailed understanding of individual SFGs has also improved greatly thanks to spatially resolved kinematic studies of the ionized gas in z ∼ 2 SFGs (e.g. SINS survey, Förster Schreiber et al. 2006, 2009; Genzel et al. 2006, 2008; Shapiro et al. 2008, 2009; Cresci et al. 2009).”
• Cool Gas in High-Redshift Galaxies (2013, background): “As opposed to either cooling of virialized, hot halo gas (White & Rees 1978), or major, gas–rich mergers (Robertson et al. 2006), the dominant mode of star formation during the epoch of galaxy assembly may be driven by cold mode accretion (CMA), aka stream– fed galaxy formation.”
• THE LONG LIVES OF GIANT CLUMPS AND THE BIRTH OF OUTFLOWS IN GAS-RICH GALAXIES AT HIGH REDSHIFT (2013, background): “…≈ 1 kpc scaleheights, Elmegreen et al. 2004) and disk-like kinematics with high turbulent velocity dispersions in both Hα and CO (Genzel et al. 2006; Shapiro et al. 2008; Bournaud et al. 2008; Contini et al. 2012; Daddi et al. 2010b ; Epinat et al. 2012; Tacconi et al. 2013, with perhaps some…”
• SPITZER QUASAR AND ULIRG EVOLUTION STUDY (QUEST). IV. COMPARISON OF 1 Jy ULTRALUMINOUS INFRARED GALAXIES WITH PALOMAR-GREEN QUASARS (2009, background): “…that the majority of the high-z ULIRGs are fed by continuous gas accretion, and only about one third are gas-rich (“wet”) mergers (Daddi et al. 2007; Shapiro et al. 2008; Genzel et al. 2006, 2008; Förster Schreiber et al. 2006, 2009; Genel et al. 2008; Dekel & Birnboim 2008; Dekel et al. 2009).”
• MERGERS AND BULGE FORMATION IN ΛCDM: WHICH MERGERS MATTER? (2009, background): “…Joseph & Wright 1985; Sanders & Mirabel 1996) to bright sub-millimeter galaxies at high redshifts (Alexander et al. 2005; Younger et al. 2008b; Shapiro et al. 2008; Tacconi et al. 2008), and properties ranging from their observed kinematics, structural correlations, and clustering link these…”
• FORMATION OF MASSIVE GALAXIES AT HIGH REDSHIFT: COLD STREAMS, CLUMPY DISKS, AND COMPACT SPHEROIDS (2009, background): “There is evidence that these clumps have formed internally in the disk (Bournaud et al. 2008; van Starkenburg et al. 2008; Shapiro et al. 2008).”
• EVIDENCE FOR WIDE-SPREAD ACTIVE GALACTIC NUCLEUS-DRIVEN OUTFLOWS IN THE MOST MASSIVE z ∼ 1–2 STAR-FORMING GALAXIES (2014, background): “…with the growing evidence that a majority of massive z ∼ 1–2.5 SFGs are disks based on kinematic and morphological properties (see also, e.g., Shapiro et al. 2008; Genzel et al. 2008, 2014a; Förster Schreiber et al. 2009; Épinat et al. 2009, 2012; Jones et al. 2010; Wuyts et al. 2011b;…”
• A study of the gas–star formation relation over cosmic time (2010, background): “Less than 50 per cent of high-z SFGs are major mergers (Shapiro et al. 2008; Förster Schreiber et al. 2009; Tacconi et al. 2010; Daddi et al. 2010a).”
• The properties of the star-forming interstellar medium at z = 0.84-2.23 from HiZELS : mapping the internal dynamics and metallicity gradients in high-redshift disc galaxies. (2012, methodology): “Although a ratio of vmax/σ = 0.4 has traditionally been used to crudely differentiate rotating systems from mergers (Förster Schreiber et al. 2009), more detailed kinematic modelling is essential to reliably differentiate rotating systems from mergers (Shapiro et al. 2008).”