scholarly journals From the outside looking in: what can Milky Way analogues tell us about the star formation rate of our own galaxy?

2019 ◽  
Vol 489 (4) ◽  
pp. 5030-5036 ◽  
Author(s):  
Amelia Fraser-McKelvie ◽  
Michael Merrifield ◽  
Alfonso Aragón-Salamanca
Keyword(s):  
Star Formation ◽  
Standard Deviation ◽  
Milky Way ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Structural Features ◽  
Mid Infrared ◽  
Recent Estimate ◽  
The Mean

ABSTRACT The Milky Way has been described as an anaemic spiral, but is its star formation rate (SFR) unusually low when compared to its peers? To answer this question, we define a sample of Milky Way analogues (MWAs) based on stringent cuts on the best literature estimates of non-transient structural features for the Milky Way. This selection yields only 176 galaxies from the whole of the SDSS DR7 spectroscopic sample which have morphological classifications in Galaxy Zoo 2, from which we infer SFRs from two separate indicators. The mean SFRs found are $\log (\rm {SFR}_{SED}/\rm {M}_{\odot }~\rm {yr}^{-1})=0.53$ with a standard deviation of 0.23 dex from SED fits, and $\log (\rm {SFR}_{W4}/\rm {M}_{\odot }~\rm {yr}^{-1})=0.68$ with a standard deviation of 0.41 dex from a mid-infrared calibration. The most recent estimate for the Milky Way’s SFR of $\log (\rm {SFR}_{MW}/\rm {M}_{\odot }~\rm {yr}^{-1})=0.22$ fits well within 2$\sigma$ of these values, where $\sigma$ is the standard deviation of each of the SFR indicator distributions. We infer that the Milky Way, while being a galaxy with a somewhat low SFR, is not unusual when compared to similar galaxies.

scholarly journals Abundance matching with the mean star formation rate: there is no missing satellites problem in the Milky Way above M200 ∼ 109 M⊙

2019 ◽  
Vol 487 (4) ◽  
pp. 5799-5812 ◽  
Author(s):  
J I Read ◽  
D Erkal
Keyword(s):  
Star Formation ◽  
Cold Dark Matter ◽  
Milky Way ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Mass Function ◽  
Accurate Estimate ◽  
Empirical Method ◽  
Galactic Centre ◽  
The Mean

ABSTRACT We introduce a novel abundance matching technique that produces a more accurate estimate of the pre-infall halo mass, M200, for satellite galaxies. To achieve this, we abundance match with the mean star formation rate, averaged over the time when a galaxy was forming stars, 〈SFR〉, instead of the stellar mass, M∗. Using data from the Sloan Digital Sky Survey, the GAMA survey and the Bolshoi simulation, we obtain a statistical 〈SFR〉−M200 relation in Λ cold dark matter. We then compare the pre-infall halo mass, $M^{\rm abund}_{200}$, derived from this relation with the pre-infall dynamical mass, $M^{\rm dyn}_{200}$, for 21 nearby dSph and dIrr galaxies, finding a good agreement between the two. As a first application, we use our new 〈SFR〉−M200 relation to empirically measure the cumulative mass function of a volume-complete sample of bright Milky Way satellites within 280 kpc of the Galactic centre. Comparing this with a suite of cosmological ‘zoom’ simulations of Milky Way-mass haloes that account for subhalo depletion by the Milky Way disc, we find no missing satellites problem above M200 ∼ 109 M⊙ in the Milky Way. We discuss how this empirical method can be applied to a larger sample of nearby spiral galaxies.

scholarly journals A Comparative Study of Mid-infrared Star Formation Rate Tracers and Their Metallicity Dependence

2020 ◽  
Vol 901 (1) ◽  
pp. 47
Author(s):  
C. M. Whitcomb ◽  
K. Sandstrom ◽  
E. J. Murphy ◽  
S. Linden
Keyword(s):  
Star Formation ◽  
Comparative Study ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Mid Infrared ◽  
Infrared Star

scholarly journals CONTINUOUS MID-INFRARED STAR FORMATION RATE INDICATORS: DIAGNOSTICS FOR 0

2015 ◽  
Vol 800 (2) ◽  
pp. 143 ◽  
Author(s):  
A. J. Battisti ◽  
D. Calzetti ◽  
B. D. Johnson ◽  
D. Elbaz
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Mid Infrared ◽  
Star Forming ◽  
Infrared Star

scholarly journals The link between solenoidal turbulence and slow star formation in G0.253+0.016

2016 ◽  
Vol 11 (S322) ◽  
pp. 123-128 ◽  
Author(s):  
C. Federrath ◽  
J. M. Rathborne ◽  
S. N. Longmore ◽  
J. M. D. Kruijssen ◽  
J. Bally ◽  
...  
Keyword(s):  
Star Formation ◽  
Mach Number ◽  
Milky Way ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Dust Emission ◽  
Volume Density ◽  
Galactic Centre ◽  
Galactic Disc ◽  
Density Variance

AbstractStar formation in the Galactic disc is primarily controlled by gravity, turbulence, and magnetic fields. It is not clear that this also applies to star formation near the Galactic Centre. Here we determine the turbulence and star formation in the CMZ cloud G0.253+0.016. Using maps of 3 mm dust emission and HNCO intensity-weighted velocity obtained with ALMA, we measure the volume-density variance σρ /ρ 0=1.3±0.5 and turbulent Mach number $\mathcal{M}$ = 11±3. Combining these with turbulence simulations to constrain the plasma β = 0.34±0.35, we reconstruct the turbulence driving parameter b=0.22±0.12 in G0.253+0.016. This low value of b indicates solenoidal (divergence-free) driving of the turbulence in G0.253+0.016. By contrast, typical clouds in the Milky Way disc and spiral arms have a significant compressive (curl-free) driving component (b > 0.4). We speculate that shear causes the solenoidal driving in G0.253+0.016 and show that this may reduce the star formation rate by a factor of 7 compared to nearby clouds.

scholarly journals Lessons from comparisons between the nuclear region of the Milky Way and those in nearby spirals

2013 ◽  
Vol 9 (S303) ◽  
pp. 61-65
Author(s):  
John S. Gallagher ◽  
Tova M. Yoast-Hull ◽  
Ellen G. Zweibel
Keyword(s):  
Star Formation ◽  
Milky Way ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Molecular Gas ◽  
Nuclear Region ◽  
Stellar Content ◽  
Nuclear Regions ◽  
Stellar Masses

AbstractThe Milky Way appears as a typical barred spiral, and comparisons can be made between its nuclear region and those of structurally similar nearby spirals. Maffei 2, M83, IC 342 and NGC 253 are nearby systems whose nuclear region properties contrast with those of the Milky Way. Stellar masses derived from NIR photometery, molecular gas masses and star formation rates allow us to assess the evolutionary states of this set of nuclear regions. These data suggest similarities between nuclear regions in terms of their stellar content while highlighting significant differences in current star formation rates. In particular current star formation rates appear to cover a larger range than expected based on the molecular gas masses. This behavior is consistent with nuclear region star formation experiencing episodic variations. Under this hypothesis the Milky Way's nuclear region currently may be in a low star formation rate phase.

scholarly journals Continuous Mid-Infrared Star Formation Rate Indicators

2014 ◽  
Vol 10 (S309) ◽  
pp. 167-168
Author(s):  
A. J. Battisti ◽  
D. Calzetti ◽  
B. D. Johnson ◽  
D. Elbaz
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Flexible Tool ◽  
Mid Infrared ◽  
Infrared Wavelength ◽  
Star Forming ◽  
James Webb Space Telescope ◽  
Multi Wavelength ◽  
Infrared Star

AbstractWe present continuous, monochromatic star formation rate (SFR) indicators over the mid-infrared wavelength range of 6–70 μm. We use a sample of 58 star forming galaxies (SFGs) in the Spitzer-SDSS-GALEX Spectroscopic Survey (SSGSS) at z<0.2, for which there is a rich suite of multi-wavelength photometry and spectroscopy from the ultraviolet through to the infrared. The data from the Spitzer infrared spectrograph (IRS) of these galaxies, which spans 5–40 μm, is anchored to their photometric counterparts. The spectral region between 40-70 μm is interpolated using dust model fits to the IRS spectrum anchored by Spitzer 70 and 160 μm photometry. Since there are no sharp spectral features in this region, we expect these interpolations to be robust. This spectral range is calibrated as a SFR diagnostic using several reference SFR indicators to mitigate potential bias. Our band-specific continuous SFR indicators are found to be consistent with monochromatic calibrations in the local universe, as derived from Spitzer, WISE, and Herschel photometry. Additionally, in the era of the James Webb Space Telescope this will become a flexible tool, applicable to any SFG up to z∼3.

scholarly journals AKARI/IRC Broadband Mid-Infrared Data as an Indicator of the Star-Formation Rate

2011 ◽  
Vol 63 (6) ◽  
pp. 1207-1217 ◽  
Author(s):  
Fang-Ting Yuan ◽  
Tsutomu T. Takeuchi ◽  
Véronique Buat ◽  
Sébastien Heinis ◽  
Elodie Giovannoli ◽  
...  
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Mid Infrared ◽  
Infrared Data

scholarly journals AKARI/IRC broadband mid-infrared data as an indicator of the Star Formation Rate

2011 ◽  
Vol 7 (S284) ◽  
pp. 357-359
Author(s):  
Fang-Ting Yuan ◽  
Tsutomu T. Takeuchi ◽  
Véronique Buat ◽  
Sébastien Heinis ◽  
Elodie Giovannoli ◽  
...  
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Infrared Camera ◽  
Far Infrared ◽  
Mid Infrared ◽  
Extended Sources ◽  
Nearby Galaxies ◽  
First Time ◽  
Infrared Data

AbstractWith the goal of constructing Star-Formation Rates (SFR) from AKARI Infrared Camera (IRC) data, we analyzed an IR-selected GALEX-SDSS-2MASS-AKARI(IRC & Far-Infrared Surveyor) sample of 153 nearby galaxies. The far-infrared fluxes were obtained from AKARI diffuse maps to correct the underestimation for extended sources raised by PSF photometry. SFRs of these galaxies were derived using the SED fitting program CIGALE. In spite of complicated features contained in these bands, both the S9W and L18W emissions correlate with the SFR of galaxies. The SFR calibrations using S9W and L18W are presented for the first time. These calibrations agree well with previous work based on Spitzer data within the scatter, and should be applicable to dust-rich galaxies.

scholarly journals Synthesis of composite stellar populations models

2009 ◽  
Vol 5 (S262) ◽  
pp. 339-340
Author(s):  
Jean Michel Gomes ◽  
R. Cid Fernandes ◽  
D. Valls-Gabaud
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Spectral Synthesis ◽  
Attenuation Factor ◽  
Formation Rate ◽  
Stellar Populations ◽  
Analytical Form ◽  
High Spectral Resolution ◽  
Population Vector ◽  
The Mean

AbstractSpectral synthesis is largely used in the literature to decompose stellar populations with integrated light of galaxies as if the star formation histories (SFH) could be approximated by single bursts. In the case of our method (see http://www.starlight.ufsc.br/ for the SEAGal - Semi Empirical Analysis of Galaxies - collaboration), the starlight code combines the spectra of simple stellar populations (SSP) of different ages and metallicities, computed with high spectral resolution evolutionary synthesis models of Bruzual & Charlot (2003), to reproduce the observed spectrum of a given galaxy from which we can derived a huge amount of galaxy properties such as: the population vector, stellar mass, extinction and others. We have done that for all galaxies of the SDSS database. Despite all the results of astrophysical interest, we have decided to use continuous composite stellar models (CSP) with a single metallicity and a star formation rate ∝ τ−1e−t/τ, where t stands for the time that the star formation started (1, 5 and 13 Gyr ago) and τ is the attenuation factor chosen to be 1, 5, 10 and 99 Gyr. When the attenuation with respect to the time t is very low, this mimics a single burst, and when we choose it to be very large (99 Gyr), this is almost a constant star formation rate. We have perturbed each composite model spectrum 10 times with three distinct signal/noise ratios equal to 10, 15 and 30 in λ0 = 4020 Å. These models were inserted into our code to verify how a picture of single bursts deal with continuous composite models of galaxies. Our CSP models can be easily integrated in an analytical form. Therefore, we have derived theoretically the mean ages and metallicities and compared them to the output derived by the synthesis. We can see that the synthesized mean ages weighted by light tend to be lower than the models, due to the degeneracies involved in the problem. The same thing can be found for the mean metallicities weighted by light, which tend to be higher for the output values.

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