MODELING DUST AND STARLIGHT IN GALAXIES OBSERVED BY<i>SPITZER</i>AND<i>HERSCHEL</i>: NGC 628 AND NGC 6946

Aniano, G.; Draine, B. T.; Calzetti, Daniela; Dale, Daniel A.; Engelbracht, C. W.; Gordon, K. D.; Hunt, L. K.; Kennicutt, Robert C.; Krause, O.; Leroy, Adam K.; Rix, H. W.; Roussel, H.; Sandström, Karin; Sauvage, M.; Walter, Fabian; Armus, L.; Bolatto, Alberto D.; Crocker, Alison F.; Meyer, Jennifer Donovan; Galametz, M.; Hélou, G.; Hinz, J. L.; Johnson, Benjamin D.; Koda, Jin; Montiel, Edward; Murphy, E. J.; Skibba, Ramin; Smith, J. D.; Wolfire, M. G.

doi:10.1088/0004-637x/756/2/138

Cited by 127 publications

(158 citation statements)

References 60 publications

Supporting

Mentioning

147

Contrasting

Order By: Relevance

“…One issue is to what level calibration differences between that of SPITZER/MIPS and that of HERSCHEL/PACS for their 160 µm data would affect the results and conclusions of the current work (see Aniano et al 2012). Another issue is the validity of the simple approach used here instead of using a more detailed dust model (e.g., Li & Draine 2001).…”

Section: B1 the Reliability Of Gas Surface Densities And Massesmentioning

confidence: 93%

Continuum observations of M 51 and M 83 at 1.1 mm with AzTEC

Wall

Puerari

Tilanus

et al. 2016

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

We observed the spiral galaxies M 51 and M 83 at 20" spatial resolution with the bolometer array AzTEC on the JCMT in the 1.1 mm continuum, recovering the extended emission out to galactocentric radii of more than 12 kpc in both galaxies. The 1.1 mm-continuum fluxes are 5.6±0.7 and 9.9±1.4 Jy, with associated gas masses estimated at 9.4 × 10 9 M and 7.2 × 10 9 M for M 51 and M 83, respectively. In the interarm regions of both galaxies the N(H 2 )/I(CO) (or X-factor) ratios exceed those in the arms by factors of ∼ 1.5-2. In the inner disks of both galaxies, the X-factor is about 1 × 10 20 cm −2 · (K · km · s −1 ) −1 . In the outer parts, the CO-dark molecular gas becomes more important.While the spiral density wave in M 51 appears to influence the interstellar medium and stars in a similar way, the bar potential in M 83 influences the interstellar medium and the stars differently. We confirm the result of Foyle et al. (2010) that the arms merely heighten the star formation rate and the gas surface density in the same proportion. Our maps reveal a threshold gas surface density for an SFR increase by two or more orders of magnitude. In both galaxy centers, the molecular gas depletion time is about 1 Gyr climbing to 10-20 Gyr at radii of 6-8 kpc. This is consistent with an inside-out depletion of the molecular gas in the disks of spiral galaxies.

show abstract

Section: B1 the Reliability Of Gas Surface Densities And Massesmentioning

confidence: 93%

Continuum observations of M 51 and M 83 at 1.1 mm with AzTEC

Wall

Puerari

Tilanus

et al. 2016

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

show abstract

“…The flux uncertainty might also be due to systematic uncertainties such as calibration errors and artifacts caused by observing cameras (e.g. Aniano et al 2012), which do not have the same properties as the statistical errors. In most cases, systematics are addressed via calibration uncertainties, because the systematics due to cameras are not well-defined.…”

Section: Sources Of Uncertaintiesmentioning

confidence: 99%

“…In most cases, systematics are addressed via calibration uncertainties, because the systematics due to cameras are not well-defined. For NGC 6946 and NGC 0628, Aniano et al (2012) investigated the systematics due to the MIPS and PACS cameras by comparing their data at a same wavelength (after convolving them to the same resolution and pixel size). For M 33, this comparison is possible only at 160 μm, because at other wavelengths the data are taken with only one camera.…”

Section: Sources Of Uncertaintiesmentioning

confidence: 99%

Variation in the dust emissivity index across M 33 withHerschelandSpitzer(HerM 33es)

Tabatabaei¹,

Braine²,

Xilouris³

et al. 2014

A&A

View full text Add to dashboard Cite

We study the wavelength dependence of the dust emission as a function of position and environment across the disk of M 33 using Spitzer and Herschel photometric data. M 33 is a Local Group spiral with slightly subsolar metallicity, which makes it an ideal stepping-stone to less regular and lower-metallicity objects such as dwarf galaxies and, probably, young-universe objects. Expressing the emissivity of the dust as a power law, the power-law exponent (β) was estimated from two independent approaches designed to properly treat the degeneracy between β and the dust temperature (T ). Both β and T are higher in the inner than in the outer disk, contrary to reported β − T anti-correlations found in other sources. In the cold + warm dust model, the warm component and the ionized gas (Hα) have a very similar distribution across the galaxy, demonstrating that the model separates the components in an appropriate way. Both cold-and warm-dust column densities are high in star-forming regions and reach their maxima toward the giant star-forming complexes NGC 604 and NGC 595. β declines from close to 2 in the center to about 1.3 in the outer disk. β is positively correlated with star formation and with the molecular gas column, as traced by the Hα and CO emission. The lower dust-emissivity index in the outer parts of M 33 is most likely related to the reduced metallicity (different grain composition) and possibly to a different size distribution. It is not due to the decrease in stellar radiation field or temperature in a simple way because the far-infrared-bright regions in the outer disk also have a low β. Like most spirals, M 33 has a (decreasing) radial gradient in star formation and molecular-to-atomic gas ratio such that the regions bright in Hα or CO tend to trace the inner disk, which makes it difficult to distinguish between their effects on the dust. The assumption of a constant emissivity index β is obviously not appropriate.

show abstract

“…The study of a single infrared surface brightness ratio has the advantage of being mainly sensitive to dust temperature changes. The exploration of multi-waveband dust spectal energy distribution (SED) fitting techniques, however, benefits from the broader wavelength coverage to study the different heating sources in several infrared wavebands (e.g., Montalto et al 2009;Aniano et al 2012;Dale et al 2012;Mentuch Cooper et al 2012;Smith et al 2012;Ciesla et al 2014;Viaene et al 2014). Panchromatic SED fitting methods are even capable of constraining the absorbed energy from star light and re-emitted photons from dust grains by postulating a dust energy balance (e.g., CIGALE, MAGPHYS and GRASIL among others).…”

Section: Introductionmentioning

confidence: 99%

High-resolution, 3D radiative transfer modeling

Looze

Fritz

Baes

et al. 2014

A&A

100

114

View full text Add to dashboard Cite

Context. Dust reprocesses about half of the stellar radiation in galaxies. The thermal re-emission by dust of absorbed energy is considered to be driven merely by young stars so is often applied to tracing the star formation rate in galaxies. Recent studies have argued that the old stellar population might be responsible for a non-negligible fraction of the radiative dust heating. Aims. In this work, we aim to analyze the contribution of young ( < ∼ 100 Myr) and old (∼10 Gyr) stellar populations to radiative dust heating processes in the nearby grand-design spiral galaxy M 51 using radiative transfer modeling. High-resolution 3D radiative transfer (RT) models are required to describe the complex morphologies of asymmetric spiral arms and clumpy star-forming regions and to model the propagation of light through a dusty medium. Methods. In this paper, we present a new technique developed to model the radiative transfer effects in nearby face-on galaxies. We construct a high-resolution 3D radiative transfer model with the Monte-Carlo code SKIRT to account for the absorption, scattering, and non-local thermal equilibrium (NLTE) emission of dust in M 51. The 3D distribution of stars is derived from the 2D morphology observed in the IRAC 3.6 µm, GALEX FUV, Hα, and MIPS 24 µm wavebands, assuming an exponential vertical distribution with an appropriate scale height. The dust geometry is constrained through the far-ultraviolet (FUV) attenuation, which is derived from the observed total-infrared-to-far-ultraviolet luminosity ratio. The stellar luminosity, star formation rate, and dust mass have been scaled to reproduce the observed stellar spectral energy distribution (SED), FUV attenuation, and infrared SED. Results. The dust emission derived from RT calculations is consistent with far-infrared and submillimeter observations of M 51, implying that the absorbed stellar energy is balanced by the thermal re-emission of dust. The young stars provide 63% of the energy for heating the dust responsible for the total infrared emission (8−1000 µm), while 37% of the dust emission is governed through heating by the evolved stellar population. In individual wavebands, the contribution from young stars to the dust heating dominates at all infrared wavebands but gradually decreases towards longer infrared and submillimeter wavebands for which the old stellar population becomes a non-negligible source of heating. Upon extrapolation of the results for M 51, we present prescriptions for estimating the contribution of young stars to the global dust heating based on a tight correlation between the dust heating fraction and specific star formation rate.

show abstract

MODELING DUST AND STARLIGHT IN GALAXIES OBSERVED BYSPITZERANDHERSCHEL: NGC 628 AND NGC 6946

Cited by 127 publications

References 60 publications

Continuum observations of M 51 and M 83 at 1.1 mm with AzTEC

Continuum observations of M 51 and M 83 at 1.1 mm with AzTEC

Variation in the dust emissivity index across M 33 withHerschelandSpitzer(HerM 33es)

High-resolution, 3D radiative transfer modeling

Contact Info

Product

Resources

About