The Star Formation Rate of the Milky Way as Seen by Herschel

Abstract

We present a new derivation of the Milky Way’s current star formation rate (SFR) based on the data of the Herschel InfraRed Galactic Plane Survey (Hi-GAL). We estimate the distribution of the SFR across the Galactic plane from the star-forming clumps identified in the Hi-GAL survey and calculate the total SFR from the sum of their contributions. The estimate of the global SFR amounts to 2.0 ± 0.7 M ⊙ yr−1, of which 1.7 ± 0.6 M ⊙ yr−1 coming from clumps with reliable heliocentric distance assignment. This value is in general agreement with estimates found in the literature of last decades. The profile of SFR density averaged in Galactocentric rings is found to be qualitatively similar to others previously computed, with a peak corresponding to the Central Molecular Zone and another one around Galactocentric radius R gal ∼ 5 kpc, followed by an exponential decrease as log ( Σ SFR / [ M ⊙ yr − 1 kpc − 2 ] ) = a R gal / [ kpc ] + b , with a = −0.28 ± 0.01. In this regard, the fraction of SFR produced within and outside the solar circle is 84% and 16%, respectively; the fraction corresponding to the far outer Galaxy (R gal > 13.5 kpc) is only 1%. We also find that, for R gal > 3 kpc, our data follow a power law as a function of density, similarly to the Kennicutt–Schmidt relation. Finally, we compare the distribution of the SFR density across the face-on Galactic plane and those of median parameters, such as temperature, luminosity/mass ratio, and bolometric temperature, describing the evolutionary stage of Hi-GAL clumps. We found no clear correlation between the SFR and the clump evolutionary stage.

Magnetic Field of Molecular Gas Measured with the Velocity Gradient Technique. II. Curved Magnetic Field in kpc-scale Bubble of NGC 628

“…The bubble number distribution along the galactocentric distance is similar to the star formation rate distribution in the Milky Way (Elia et al 2022). The bubble scale of ∼50 pc could be typical for NGC 628 and is similar to the largest SNRs found in the Milky Way (Ostriker & McKee 1988;Becker et al 2021).…”

One, Two, Three ... An Explosive Outflow in IRAS 12326-6245 Revealed by ALMA

“…Alternatively, we can compare this rate also to the massive star (8 M e ) formation rate, that can be estimated as follows. The global star formation rate in the Milky Way is ∼2 M e yr −1 (Elia et al 2022). Since the average mass of stars in the initial mass function is ∼0.5 M e (Parravano et al 2006), we expect that 4 stars form per year.…”

Evidence of high-mass star formation through multi-scale mass accretion in hub-filament-system clouds

“…The clumps in IR-dark and bright HFSs have a median L bol /M clump value of 0.14 L /M in a range of [0.04, 0.46] L /M , and a median value of 105 L /M in a range of [3.58, 204.62] L /M , respectively. The ratio L bol /M clump has been used as a diagnostic tool to probe the evolutionary stages of observed clumps (e.g., Urquhart et al 2014;Giannetti et al 2017;Elia et al 2022). Based on the results discussed in these papers, values of L bol /M clump 2 have been associated with a very early evolutionary phase of mass accretion and possibly the beginning of protostellar activity.…”