TY - JOUR

T1 - The universal acceleration scale from stellar feedback

AU - Grudić, Michael Y.

AU - Boylan-Kolchin, Michael

AU - Faucher-Giguère, Claude André

AU - Hopkins, Philip F.

N1 - Funding Information:
Alfred P. Sloan Research Fellowship, NSF Collaborative Research Grant #1715847 and CAREER grant #1455342, and NASA grants NNX15AT06G, JPL 1589742, and 17-ATP17-0214.
Funding Information:
We thank James Bullock, Manoj Kaplinghat, and Jonathan Stern for useful discussions, and the anonymous referees for various comments that improved and clarified this work. MYG was supported by the CIERA Postdoctoral Fellowship Program. MBK acknowledges support from NSF grants AST-1517226, AST-1910346, and CAREER award AST-1752913, NASA grant NNX17AG29G, and grants HST-AR-13888, HST-AR-13896, HST-AR-14282, HST-AR-14554, HST-AR-15006, HST-GO-12914, and HST-GO-14191 from the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555. CAFG was supported by NSF through grants AST-1517491, AST-1715216, and CAREER award AST-1652522, by NASA through grant 17-ATP17-0067, and by a Cottrell Scholar Award from the Research Corporation for Science Advancement. Support for PFH was provided by an
Publisher Copyright:
© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.

PY - 2020/5/22

Y1 - 2020/5/22

N2 - It has been established for decades that rotation curves deviate from the Newtonian gravity expectation given baryons alone below a characteristic acceleration scale $g-{dagger }sim 10{-8}, rm {cm, s{-2}}$, a scale promoted to a new fundamental constant in MOND. In recent years, theoretical and observational studies have shown that the star formation efficiency (SFE) of dense gas scales with surface density, SFE ∼ς/ςcrit with $Sigma{rm crit} sim langle dot{p}/m-{ast }rangle /(pi , G)sim 1000, rm {M-{odot }, pc{-2}}$ (where $langle dot{p}/m-{ast }rangle$ is the momentum flux output by stellar feedback per unit stellar mass in a young stellar population). We argue that the SFE, more generally, should scale with the local gravitational acceleration, i.e. that SFE ${sim}g-{rm tot}/g-{rm crit}equiv (G, M-{rm tot}/R{2}) / langle dot{p}/m-{ast }rangle$, where Mtot is the total gravitating mass and $g-{rm crit}=langle dot{p}/m-{ast }rangle = pi , G, Sigma -{rm crit} approx 10{-8}, rm {cm, s{-2}} approx mathit{ g}-{dagger }$. Hence, the observed g† may correspond to the characteristic acceleration scale above which stellar feedback cannot prevent efficient star formation, and baryons will eventually come to dominate. We further show how this may give rise to the observed acceleration scaling $g-{rm obs}sim (g-{rm baryon}, g-{dagger }){1/2}$ (where gbaryon is the acceleration due to baryons alone) and flat rotation curves. The derived characteristic acceleration g† can be expressed in terms of fundamental constants (gravitational constant, proton mass, and Thomson cross-section): $g-{dagger }sim 0.1, G, m-{mathrm{ p}}/sigma -{rm T}$.

AB - It has been established for decades that rotation curves deviate from the Newtonian gravity expectation given baryons alone below a characteristic acceleration scale $g-{dagger }sim 10{-8}, rm {cm, s{-2}}$, a scale promoted to a new fundamental constant in MOND. In recent years, theoretical and observational studies have shown that the star formation efficiency (SFE) of dense gas scales with surface density, SFE ∼ς/ςcrit with $Sigma{rm crit} sim langle dot{p}/m-{ast }rangle /(pi , G)sim 1000, rm {M-{odot }, pc{-2}}$ (where $langle dot{p}/m-{ast }rangle$ is the momentum flux output by stellar feedback per unit stellar mass in a young stellar population). We argue that the SFE, more generally, should scale with the local gravitational acceleration, i.e. that SFE ${sim}g-{rm tot}/g-{rm crit}equiv (G, M-{rm tot}/R{2}) / langle dot{p}/m-{ast }rangle$, where Mtot is the total gravitating mass and $g-{rm crit}=langle dot{p}/m-{ast }rangle = pi , G, Sigma -{rm crit} approx 10{-8}, rm {cm, s{-2}} approx mathit{ g}-{dagger }$. Hence, the observed g† may correspond to the characteristic acceleration scale above which stellar feedback cannot prevent efficient star formation, and baryons will eventually come to dominate. We further show how this may give rise to the observed acceleration scaling $g-{rm obs}sim (g-{rm baryon}, g-{dagger }){1/2}$ (where gbaryon is the acceleration due to baryons alone) and flat rotation curves. The derived characteristic acceleration g† can be expressed in terms of fundamental constants (gravitational constant, proton mass, and Thomson cross-section): $g-{dagger }sim 0.1, G, m-{mathrm{ p}}/sigma -{rm T}$.

KW - cosmology: dark matter

KW - galaxies: evolution

KW - galaxies: formation

UR - http://www.scopus.com/inward/record.url?scp=85087007859&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85087007859&partnerID=8YFLogxK

U2 - 10.1093/mnrasl/slaa103

DO - 10.1093/mnrasl/slaa103

M3 - Article

AN - SCOPUS:85087007859

SN - 1745-3933

VL - 496

SP - L127-L132

JO - Monthly Notices of the Royal Astronomical Society: Letters

JF - Monthly Notices of the Royal Astronomical Society: Letters

IS - 1

ER -