DISSIPATION AND EXTRA LIGHT IN GALACTIC NUCLEI. IV. EVOLUTION IN THE SCALING RELATIONS OF SPHEROIDS

By P. Hopkins, L. Hernquist, Thomas J. Cox, D. Keres̆, S. Wuyts. 2008

211 citations recorded by the source corpus.

We develop a model for the physical origin and redshift evolution of spheroid scaling relations. We consider spheroid sizes, velocity dispersions, dynamical masses, profile shapes (Sérsic indices), stellar and supermassive black hole (BH) masses, and their related scalings. Our approach combines advantages of prior observational constraints in halo occupation models and libraries of high-resolution hydrodynamic simulations of galaxy mergers. This allows us to separate the relative roles of dissipation, dry mergers, formation time, and evolution in progenitor properties, and identify their impact on observed scalings at each redshift. We show that, at all redshifts, dissipation is the most important factor determining spheroid sizes and fundamental plane scalings, and can account (at z = 0) for the observed fundamental plane tilt and differences between observed disk and spheroid scaling relations. Because disks (spheroid progenitors) at high redshift have characteristically larger gas fractions, this predicts more dissipation in mergers, yielding systematically more compact, smaller spheroids. In detail, this gives rise to a mass-dependent evolution in the sizes of spheroids of a given mass, which agrees well with observations. This relates to a subtle weakening of the tilt of the early-type fundamental plane with redshift, important for a number of studies that assume a nonevolving stellar mass fundamental plane. This also predicts evolution in the BH–host mass relations, toward more massive BHs at higher redshifts. Dry mergers are also significant, but only for large systems which form early—they originate as compact systems, but undergo a number of dry mergers (consistent with observations) such that they have sizes at any later observed redshift similar to systems of the same mass formed more recently. Most of the observed, compact high-redshift ellipticals will become the cores of present brightest cluster galaxies, and we show how their sizes, velocity dispersions, and BH masses evolve to become consistent with observations. We also predict what fraction might survive intact from early formation and identify their characteristic z = 0 properties. We make predictions for residual correlations as well, e.g., the correlation of size and fundamental plane residuals with formation time of a given elliptical, that can be used as additional tests of these models.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/18961c6ce8459f7bfb9210706d9765d2dfb98938

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In Astronomy and Astrophysics

1. P. Hopkins
2. L. Hernquist
3. R. Somerville
4. Volker Springel
5. R. Dav'e
6. T. Naab
7. M. Cappellari
8. Thomas J. Cox

Citations in the corpus

• How do minor mergers promote inside-out growth of ellipticals, transforming the size, density profile and dark matter fraction? (2012, background): “Even if the progenitor disks were gas-rich leading to a compact remnant (Ricciardelli et al. 2010; Wuyts et al. 2010; Bournaud et al. 2011) those would have to evolve further by a separate process (see e.g. Hopkins et al. 2009).”
• Erratum: From dwarf spheroidals to cD galaxies: simulating the galaxy population in a ΛCDM cosmology (2010, background): “At lower masses, our default model predicts a larger median value than is observed, perhaps reflecting gas dissipation during gas-rich mergers (e.g. Hopkins et al. 2009).”
• ON SIZES, KINEMATICS, M/L GRADIENTS, AND LIGHT PROFILES OF MASSIVE COMPACT GALAXIES AT z ∼ 2 (2010, methodology): “…later times, they find that minor and gas-poor merging forms an efficient means to build up an envelope around this core (see also Section 6.3 of this paper, and Hopkins et al. 2009a).4 In the scenario investigated in this paper, the initial dissipational event occurs in the form of a major merger.”
• EXTREME FEEDBACK AND THE EPOCH OF REIONIZATION: CLUES IN THE LOCAL UNIVERSE (2011, result): “Finally, we note that O09 have shown that the masses and sizes of the DCOs are consistent with the regions of excess mass (cusps) seen in the centers of typical presentday M∗ elliptical galaxies (Hopkins et al. 2009).”
• The effects of gas on morphological transformation in mergers: implications for bulge and disc demographics (2009, methodology): “In practice, many of these bulges are made by minor mergers, but the relative suppression is similar (Hopkins et al. 2009e; Weinzirl et al. 2009).”
• THE TWO PHASES OF GALAXY FORMATION (2010, background): “A recent paper by Hopkins et al. (2009) shows how useful this picture can be.”
• Dissecting the size evolution of elliptical galaxies since z∼ 1: puffing-up versus minor-merging scenarios (2011, background): “Another possible scenario for elliptical galaxy growth involves minor mergers on parabolic orbits (e.g. Khochfar & Burkert 2006; Maller et al. 2006; Hopkins et al. 2009b; Naab et al. 2009) .”
• AGN-driven quenching of star formation: morphological and dynamical implications for early-type galaxies (2013, background): “…2006b; Maller et al. 2006; Naab, Khochfar & Burkert 2006; Bournaud, Jog & Combes 2007; De Lucia & Blaizot 2007; Naab et al. 2007; Guo & White 2008; Hopkins et al. 2009; Nipoti et al. 2009; Feldmann et al. 2010; Shankar et al. 2013), and is supported by the direct evidence of merger remnants of…”
• Nuclear star clusters (2009, unknown): “However, this interpretation is controversial, as Hopkins et al. (2009) and Kormendy and Ho (2013) further subdivide this group of lower-mass early-type galaxies into ellipticals with central light excess on the one hand, and diskier spheroidals with NSCs on the other.”
• THE EVOLVING RELATIONS BETWEEN SIZE, MASS, SURFACE DENSITY, AND STAR FORMATION IN 3 × 104 GALAXIES SINCE z = 2 (2009, background): “Several mechanisms for this transformation have been proposed, including a scenario whereby local early-type galaxies are built through a series of “dry” (i.e., gas-poor) mergers of these compact progenitors (Khochfar & Silk 2008; Hopkins et al. 2009b; Feldmann et al. 2009).”
• MINOR MERGERS AND THE SIZE EVOLUTION OF ELLIPTICAL GALAXIES (2009, background): “5)(see also Hopkins et al. 2009).”
• GALAXY STRUCTURE AND MODE OF STAR FORMATION IN THE SFR–MASS PLANE FROM z ∼ 2.5 TO z ∼ 0.1 (2011, result): “Massive (∼ 1011 M⊙) quiescent galaxies at high redshift are increasingly more compact relative to similar mass galaxies today (re/re, z=0 ∼ (1+ z) −1.1±0.2) (e.g., van der Wel et al. 2008; van Dokkum et al. 2008, but see Mancini et al. 2010 for a contrasting view), in agreement with expectations fro”
• THE GROWTH OF MASSIVE GALAXIES SINCE z = 2 (2009, background): “As noted by Franx et al. (2008); Hopkins et al. (2009c); Bezanson et al. (2009); Cenarro & Trujillo (2009) and others, a proper comparison would consider all progenitors, not just the quiescent galaxies, and explicitly take mass evolutioninto account.”
• Compact high-redshift galaxies are the cores of the most massive present-day spheroids (2009, background): “This is a relatively efficient channel for size–mass evolution, yielding a factor of several size evolution with only a factor of 1.5–2 increase in stellar mass (Hopkins et al. 2009d).”
• How do massive black holes get their gas (2009, methodology): “This process has been described in detail in e.g. Hopkins et al. (2009c) and references therein, but for completeness we briefly summarize the important physics.”
• The DEEP3 Galaxy Redshift Survey: the impact of environment on the size evolution of massive early-type galaxies at intermediate redshift (2011, background): “…types at z ∼ 2 are found to only exceed local C© 2011 The Authors Monthly Notices of the Royal Astronomical Society C© 2011 RAS nras/article-abstract/419/4/3018/2908043 by guest on 15 M arch 2020 measurements by a factor of 2–3 (Bezanson et al. 2009; Hopkins et al. 2009a; van Dokkum et al. 2010).”
• THE NEXT GENERATION VIRGO CLUSTER SURVEY (NGVS). I. INTRODUCTION TO THE SURVEY (2012, background): “Li et al. (2007) argued that the observed relation may be a consequence of gas depletion via accretion and star formation, while Hopkins et al. (2009) have shown that star formation triggered by gas inflows during mergers would lead to embedded stellar components with properties similar to those…”
• Theoretical Challenges in Galaxy Formation (2016, methodology): “…infrared galaxies (ULIRGS) and explain observations of ’extra light’ in the centers of low mass early-type galaxies (Hayward et al. 2014; Hopkins et al. 2009a, 2013, 2009c; Kormendy 1999; Kormendy et al. 2009; Mihos & Hernquist 1994a,c, 1996; Springel 2000; Teyssier, Chapon & Bournaud…”
• How Stellar Feedback Simultaneously Regulates Star Formation and Drives Outflows (2015, background): “We not that suppression of starbursts is especially undesirable becaus they are critical for making realistic bulges (Hopkins et al. 2008, 2009a,c).”