Was the Milky Way a chain galaxy? Using the IGIMF theory to constrain the thin-disc star formation history and mass

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F19%3A10406392" target="_blank" >RIV/00216208:11320/19:10406392 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=26xo5mh-og" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=26xo5mh-og</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/mnras/sty2812" target="_blank" >10.1093/mnras/sty2812</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Was the Milky Way a chain galaxy? Using the IGIMF theory to constrain the thin-disc star formation history and mass

Popis výsledku v původním jazyce

The observed present-day stellar mass function (PDMF) of the solar neighbourhood is a mixture of stellar populations born in star-forming events that occurred over the lifetime of the thin disc of the Galaxy. Assuming stars form in embedded clusters which have stellar initial mass functions (IMFs) which depend on the metallicity and density of the star-forming gas clumps, the integrated galaxy-wide IMF (IGIMF) can be calculated. The shape of the IGIMF thus depends on the star formation rate (SFR) and metallicity. Here, the shape of the PDMF for stars more massive than 1M(circle dot) in combination with the mass density in low-mass stars is used to constrain the current SFR, the star formation history (SFH), and the current stellar plus remnant mass (M-*) in the Galactic thin disc. This yields the current SFR, (M) over dot(*) = 4.1(-2.8)(+3.1)M(circle dot) yr(-1), a declining SFH, and M-* = 2.1(-1.5)(+3.0) x 10(11) M-circle dot, respectively, with a V-band stellar mass-to-light ratio of M-*/L-V = 2.79(-0.38)(+0.48). These values are consistent with independent measurements. We also quantify the surface density of black holes and neutron stars in the Galactic thin disc. The invariant canonical IMF can reproduce the PDMF of the Galaxy as well as the IGIMF, but in the universal IMF framework it is not possible to constrain any of the above Galactic properties. Assuming the IGIMF theory is the correct framework and in combination with the vertical velocity dispersion data of stars, it follows that the Milky Way would have appeared as a chain galaxy at high redshift.

Název v anglickém jazyce

Was the Milky Way a chain galaxy? Using the IGIMF theory to constrain the thin-disc star formation history and mass

Popis výsledku anglicky

The observed present-day stellar mass function (PDMF) of the solar neighbourhood is a mixture of stellar populations born in star-forming events that occurred over the lifetime of the thin disc of the Galaxy. Assuming stars form in embedded clusters which have stellar initial mass functions (IMFs) which depend on the metallicity and density of the star-forming gas clumps, the integrated galaxy-wide IMF (IGIMF) can be calculated. The shape of the IGIMF thus depends on the star formation rate (SFR) and metallicity. Here, the shape of the PDMF for stars more massive than 1M(circle dot) in combination with the mass density in low-mass stars is used to constrain the current SFR, the star formation history (SFH), and the current stellar plus remnant mass (M-*) in the Galactic thin disc. This yields the current SFR, (M) over dot(*) = 4.1(-2.8)(+3.1)M(circle dot) yr(-1), a declining SFH, and M-* = 2.1(-1.5)(+3.0) x 10(11) M-circle dot, respectively, with a V-band stellar mass-to-light ratio of M-*/L-V = 2.79(-0.38)(+0.48). These values are consistent with independent measurements. We also quantify the surface density of black holes and neutron stars in the Galactic thin disc. The invariant canonical IMF can reproduce the PDMF of the Galaxy as well as the IGIMF, but in the universal IMF framework it is not possible to constrain any of the above Galactic properties. Assuming the IGIMF theory is the correct framework and in combination with the vertical velocity dispersion data of stars, it follows that the Milky Way would have appeared as a chain galaxy at high redshift.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Monthly Notices of the Royal Astronomical Society

ISSN

0035-8711

e-ISSN

—

Svazek periodika

483

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

11

Strana od-do

46-56

Kód UT WoS článku

000462251000004

EID výsledku v databázi Scopus

2-s2.0-85063903778