DIFFERENT STAR FORMATION LAWS FOR DISKS VERSUS STARBURSTS AT LOW AND HIGH REDSHIFTS

By E. Daddi, D. Elbaz, F. Walter, Frédéric Bournaud, F. Salmi, C. Carilli, H. Dannerbauer, Mark Dickinson, P. Monaco, D. Riechers. 2010

529 citations recorded by the source corpus.

We present evidence that bona fide disks and starburst systems occupy distinct regions in the gas mass versus star formation rate (SFR) plane, both for the integrated quantities and for the respective surface densities. This result is based on carbon monoxide (CO) observations of galaxy populations at low and high redshifts, and on the current consensus for the CO luminosity to gas mass conversion factors. The data suggest the existence of two different SF regimes: a long-lasting mode for disks and a more rapid mode for starbursts, the latter probably occurring during major mergers or in dense nuclear SF regions. Both modes are observable over a large range of SFRs. The detection of CO emission from distant near-IR selected galaxies reveals such bimodal behavior for the first time, as they allow us to probe gas in disk galaxies with much higher SFRs than are seen locally. The different regimes can potentially be interpreted as the effect of a top-heavy initial mass function in starbursts. However, we favor a different physical origin related to the fraction of molecular gas in dense clouds. The IR luminosity to gas mass ratio (i.e., the SF efficiency) appears to be inversely proportional to the dynamical (rotation) timescale. Only when accounting for the dynamical timescale, a universal SF law is obtained, suggesting a direct link between global galaxy properties and the local SFR.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/059463c2ac5c56a4dc63b1e1799a53b32952ef15

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. Somerville
4. R. Dav'e
5. A. Dekel
6. D. Narayanan
7. D. M. Alexander
8. T. Naab

Citations in the corpus

• Galaxies on FIRE (Feedback In Realistic Environments): stellar feedback explains cosmologically inefficient star formation (2013, methodology): “15 We compile the observed local galaxies in Kennicutt (1998) and Bigiel et al. (2008), and high-redshift galaxies in Genzel et al. (2010) and Daddi et al. (2010); shaded region shows the 90% inclusion range at each Σgas from the compilation.”
• The star formation main sequence and stellar mass assembly of galaxies in the Illustris simulation (2014, background): “…compared with normal galaxies, starbursts account for only a small fraction (∼ 5 − 10 per cent) of the global SFR density (Rodighiero et al. 2011) because they are rare and short-lived (because of their short gas-consumption timescales; Knapen & James 2009; Genzel et al. 2010; Daddi et al. 2010).”
• The assembly of ‘normal’ galaxies at z ∼ 7 probed by ALMA (2015, methodology): “…tool to trace the evolution of the gas and dust content (e.g. Tacconi et al. 2013; Santini et al. 2014; Bothwell et al. 2013; Genzel et al. 2010; Daddi et al. 2010; Carilli & Walter 2013), to investigate their dynamics (e.g. Wang et al. 2013; De Breuck et al. 2014; Carniani et al. 2013; Carilli…”
• THE CONTRIBUTION OF STARBURSTS AND NORMAL GALAXIES TO INFRARED LUMINOSITY FUNCTIONS AT z < 2 (2012, background): “…Differences between the shape of the IR spectral energy distribution (SED; Elbaz et al. 2011) of these two kinds of systems and the different efficiency with which they convert molecular gas to stars (Daddi et al. 2010b, Genzel et al. 2010) have given rise to the notion of “bimodal” star formation.”
• THE MOLECULAR GAS IN LUMINOUS INFRARED GALAXIES. II. EXTREME PHYSICAL CONDITIONS AND THEIR EFFECTS ON THE Xco FACTOR (2012, background): “It is worth noting that the claimed bimodality of the Schmidt-Kennicutt star formation relations (linking SFR and molecular gas supply) between disks and mergers (Daddi et al. 2010a; Genzel et al. 2010) is nearly equivalent to such an Xco bimodality (Narayanan et al. 2010 and references therein).”
• PHIBSS: MOLECULAR GAS CONTENT AND SCALING RELATIONS IN z ∼ 1–3 MASSIVE, MAIN-SEQUENCE STAR-FORMING GALAXIES (2012, background): “Most objects in this region appear to be dominated by short-lived starburst events with ~5-50 times smaller depletion time scales than in the main-sequence SFGs (Daddi et al. 2010b, Genzel et al. 2010, Magnelli et al. 2012a).”
• A study of the gas–star formation relation over cosmic time (2010, methodology): “2.3 〈z〉 = 1.5 sample In addition, we included in our analysis six 〈z〉 = 1.5 SFGs from Daddi et al. (2008, 2010a).”
• STAR FORMATION RELATIONS IN NEARBY MOLECULAR CLOUDS (2014, background): “This relation may also be useful for understanding starburst galaxies (Daddi et al. 2010; Genzel et al. 2010), but it cannot be extended to the level of molecular clouds in the MW (e.g., Krumholz et al. 2012).”
• A unified model for galactic discs: star formation, turbulence driving, and mass transport (2017, methodology): “In plotting the data we use the CO-H2 conversion factor αCO recommended by Daddi et al. (2010b), and we discuss this choice further in Appendix A.”
• Tracing the molecular gas in distant submillimetre galaxies via CO(1-0) imaging with the EVLA (2010, methodology): “2), then one might argue that SMGs and ULIRGs populate a different sequence to BzK and spiral galaxies, as did Daddi et al. (2010).”
• THE LESSER ROLE OF STARBURSTS IN STAR FORMATION AT z = 2 (2011, background): “This is actually much shorter than both the gas depletion timescale and the (outer rotation) dynamical time in starburst galaxies (Daddi et al. 2010; Genzel et al. 2010).”
• THE DRIVING MECHANISM OF STARBURSTS IN GALAXY MERGERS (2010, background): “…a dual law for SF, where the integrated gas consumption timescale (ΣSFR/Σgas) is relatively low for quiescent star-forming disks and higher for starbursting ULIRGs and sub-millimeter galaxies (likely major mergers), as pointed out independently by Daddi et al. (2010a) and Genzel et al. (2010).”
• HYDRODYNAMICS OF HIGH-REDSHIFT GALAXY COLLISIONS: FROM GAS-RICH DISKS TO DISPERSION-DOMINATED MERGERS AND COMPACT SPHEROIDS (2010, background): “The spectrum is more complex than the usual double-horn profile observed for rotating gas disks (including clumpy high-redshift disks, Daddi et al. 2010), and is best fitted by a combination of four main emitting components.”
• A HIGHLY CONSISTENT FRAMEWORK FOR THE EVOLUTION OF THE STAR-FORMING “MAIN SEQUENCE” FROM z ∼ 0–6 (2014, result): “Taken together with observations that the ES relation encompasses a broader range of galaxy classes than the KS relation while proving equally good fits (Daddi et al. 2010; Magdis et al. 2012), we interpret this as tentative evidence supporting the ES view of star formation.”
• The applicability of far-infrared fine-structure lines as star formation rate tracers over wide ranges of metallicities and galaxy types (2014, background): “…modes of star formation (Graciá-Carpio et al. 2011), i.e., the star-forming disk galaxies populating the main sequence in the gas-star formation diagrams and ultra-luminous gas-rich mergers with elevated levels of star formation for the same gas fractions (Daddi et al. 2010; Genzel et al. 2010).”
• GAS AND DUST IN A SUBMILLIMETER GALAXY AT z = 4.24 FROM THE HERSCHEL ATLAS (2011, background): “This threshold is similar to the one separating the star formation relations between non- or weakly-interacting starforming galaxies and luminous mergers (Genzel et al. 2010, Daddi et al. 2010).”
• Self-regulated star formation in galaxies via momentum input from massive stars (2011, methodology): “Grey shaded region shows the 90 per cent completeness range at each gas surface density from the compilation of the systems observed in those two works as well as the compilations in Bigiel et al. (2008) and Daddi et al. (2010).”
• Evolution of the dust emission of massive galaxies up to z=4 and constraints on their dominant mode of star formation (2014, background): “This difference can be understood if we consider that galaxies are driven by two types of star formation activity: smooth processes fed by large reservoirs of gas in normal star-forming galaxies and boosted star-formation in gas rich mergers (Daddi et al. 2010b; Genzel et al. 2010).”