The galaxy stellar mass-star formation rate relation: evidence for an evolving stellar initial mass function?

By R. Dav'e. 2007

268 citations recorded by the source corpus.

The evolution of the galaxy stellar mass-star formation rate relationship (M*-SFR) provides key constraints on the stellar mass assembly histories of galaxies. For star-forming galaxies, M*-SFR is observed to be fairly tight with a slope close to unity from z ∼ 0 → 2, and it evolves downwards roughly independently of M*. Simulations of galaxy formation reproduce these trends, broadly independent of modelling details, owing to the generic dominance of smooth and steady cold accretion in these systems. In contrast, the observed amplitude of the M*-SFR relation evolves markedly differently than in models, indicating either that stellar mass assembly is poorly understood or that observations have been misinterpreted. Stated in terms of a star formation activity parameter α sf ≡ (M* /SFR)/(t Hubble -1 Gyr), models predict a constant α sf ∼ 1 out to redshifts z ∼ 4+, while the observed M*-SFR relation indicates that α sf increases by approximately three times from z ∼ 2 until today. The low α sf (i.e. rapid star formation) at high z not only conflicts with models, but also difficult to reconcile with other observations of high-z galaxies, such as the small scatter in M*-SFR, the slow evolution of star-forming galaxies at z ∼ 2-4 and the modest passive fractions in mass-selected samples. Systematic biases could significantly affect measurements of M* and SFR, but detailed considerations suggest that none are obvious candidates to reconcile the discrepancy. A speculative solution is considered in which the stellar initial mass function (IMF) evolves towards more high-mass star formation at earlier epochs. Following Larson, a model is investigated in which the characteristic mass M where the IMF turns over increases with redshift. Population synthesis models are used to show that the observed and predicted M*-SFR evolution may be brought into broad agreement if M = 0.5 (1 + z) 2 M ⊙ out to z ∼ 2. Such IMF evolution matches recent observations of cosmic stellar mass growth, and the resulting z = 0 cumulative IMF is similar to the 'paunchy' IMF favoured by Fardal et al. to reconcile the observed cosmic star formation history with present-day fossil light measures.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/540a5ece2132034ffe503c92de24faa7672caf54

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

In Instrumentation

Citations in the corpus

A STEEP FAINT-END SLOPE OF THE UV LUMINOSITY FUNCTION AT z ∼ 2–3: IMPLICATIONS FOR THE GLOBAL STELLAR MASS DENSITY AND STAR FORMATION IN LOW-MASS HALOS (2008, background): “This results in factor of ∼ 1.7 decrease in SFR for a given luminosity owing to the larger fractional contribution of high-mass stars to the Kroupa relative to the Salpeter (1955) IMF.”
THE EVOLUTIONARY HISTORY OF LYMAN BREAK GALAXIES BETWEEN REDSHIFT 4 AND 6: OBSERVING SUCCESSIVE GENERATIONS OF MASSIVE GALAXIES IN FORMATION (2009, background): “The first is the possibility of an evolving initial mass function (Davé 2008; van Dokkum 2008) in which the characteristic stellar mass increases toward higher redshifts.”
The star formation main sequence and stellar mass assembly of galaxies in the Illustris simulation (2014, background): “Potential solutions to this problem have been suggested, including a varying IMF (Davé 2008) and modification of the timescale for reincorporation of gas ejected by feedback processes (Mitchell et al. 2014).”
A fundamental problem in our understanding of low-mass galaxy evolution (2012, methodology): “An alternative form of GSW feedback, based on momentum-conserving processes, has been proposed by Oppenheimer & Davé (2006), Oppenheimer & Davé (2008), Davé et al. (2011a, b).”
On the origin of the galaxy star‐formation‐rate sequence: evolution and scatter (2009, methodology): “The discrepancies between the SSFRs in our models and the data at z 2 are of similar (but smaller) magnitude and direction as found by Davé (2008), using cosmological hydrodynamical simulations.”
Galaxies in a simulated ΛCDM Universe – I. Cold mode and hot cores (2008, background): “However, the normalization of the simulated relation is lower than that observed (see Davé 2008).”
KECK SPECTROSCOPY OF 3 < z < 7 FAINT LYMAN BREAK GALAXIES: THE IMPORTANCE OF NEBULAR EMISSION IN UNDERSTANDING THE SPECIFIC STAR FORMATION RATE AND STELLAR MASS DENSITY (2012, background): “Previous theoretical studies have focused on a variety of explanations for the tension at z ≃ 2, including a time-varying initial mass function (e.g., Davé 2008, Narayanan & Davé 2012).”
The evolution of massive black holes and their spins in their galactic hosts (2012, background): “Another possibility is that the IMF might evolve with redshift (Wilkins, Trentham, & Hopkins 2008; Wilkins et al.2008; Davé 2008), and there are in fact theoretical arguments andindirect observational evidence for that (van Dokkum 2008; Larson 2005; Wang & Dai 2011).”
simba: Cosmological simulations with black hole growth and feedback (2019, background): “Measurements of the gas-phase metallicity reflect a balance between relatively pristine inflow and ejection of enriched material via outflows, and thus provide a direct constraint on the mass outflow rate in gas-rich (star-forming) galaxies (Finlator & Davé 2008).”
A semi-analytic model for the co-evolution of galaxies, black holes and active galactic nuclei (2008, background): “…data better, while the WMAP3 model provides a better fit to the stellar mass density) is connected with a possible inconsistency between the two data sets that has been noted recently in several papers (e.g. Hopkins & Beacom 2006; Fardal et al. 2007; Davé 2008; Wilkins, Trentham & Hopkins 2008).”
Production of dust by massive stars at high redshift (2011, background): “, Elmegreen, 2009) while the IMF in the early Universe and in starburst gal axies may be biased towards high-mass stars (e.g., Doane and Mathews, 1993; Davé, 2008 ; Dabringhausen et al, 2009; Habergham et al, 2010).”
Discriminating Between the Physical Processes that Drive Spheroid Size Evolution (2009, background): “Likewise, redshift evolution in the stellar initial mass function, suggested (indirectly) by some observations (Hopkins & Beacom 2006; Davé 2008; van Dokkum 2008), could yield a similar effect.”
SHORT-LIVED STAR-FORMING GIANT CLUMPS IN COSMOLOGICAL SIMULATIONS OF z ≈ 2 DISKS (2010, methodology): “We have, however, modified the Oppenheimer & Davé (2008) code to ensure that the velocity kicks are perpendicular to the disk (e.g. Bordoloi et al. 2011, Bouché et al. in prep.).”
Star formation and mass assembly in high-redshift galaxies (2009, background): “This disagreement could be alleviated by an evolving IMF (Wilkins et al. 2008; Davé 2008), which would provide lower values of SFR.”
Structure and Star Formation in Galaxies out to z = 3: Evidence for Surface Density Dependent Evolution and Upsizing (2008, background): “In addition, the IMF of the stars may vary (e.g., van Dokkum 2008, Davé 2008, Wilkins& Hopkins et al. 2008).”
NIHAO project – I. Reproducing the inefficiency of galaxy formation across cosmic time with a large sample of cosmological hydrodynamical simulations (2015, background): “A Milky Way IMF in spiral galaxies is consistent with dynamical based massto-light ratios (Courteau & Dutton 2015).”
Dusty Star Forming Galaxies at High Redshift (2014, background): “Davé (2008) note that most cosmological simulations are unable to match the observed SFRs of main sequence galaxies at z ∼ 2 (at a given stellarmass), and suggest that even amildly bottom light IMF in these systemsmay go somedistance towards reducing the inferred SFRs of z ∼ 2 galaxies enough to…”
The Herschel census of infrared SEDs through cosmic time (2013, background): “However, although more strongly star-forming galaxies such as ULIRGs are predominantly more massive (e.g. Davé 2008; Shapley 2011) and dustier systems (e.g. Magdis et al. 2012) with warmer average dust temperatures, we find that their SED shapes are not substantially different to their lower…”
THE SINS SURVEY OF z ∼ 2 GALAXY KINEMATICS: PROPERTIES OF THE GIANT STAR-FORMING CLUMPS (2010, background): “This “star formation feedback” is widely thought to be a key ingredient in the evolution of starforming galaxies (Dekel & Silk 1986; Kauffmann et al. 1993; Finlator & Davé 2008; Efstathiou 2000; Bouché et al. 2010; Dutton et al. 2010).”