Toward a Removal of Temperature Dependencies From Abundance Determinations: NGC 628

Croxall, K. V.; Smith, John David; Brandl, Bernhard R.; Groves, Brent; Kennicutt, Robert C.; Kreckel, Kathryn; Johnson, Benjamin D.; Pellegrini, E.; Sandström, Karin; Walter, Fabian; Armus, L.; Beirão, P.; Calzetti, Daniela; Dale, Daniel A.; Galametz, M.; Hinz, J. L.; Hunt, L. K.; Koda, Jin; Schinnerer, E.

doi:10.1088/0004-637x/777/2/96

Cited by 40 publications

(52 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The data and the associated reduction are described in Kennicutt et al (2011) andCroxall et al (2013). We have extracted line and continuum fluxes from regions corresponding to the positions and sizes of the SPIRE-FTS bolometers.…”

Section: Pacs Photometry and Spectroscopymentioning

confidence: 99%

The Origins of [C ii] Emission in Local Star-forming Galaxies

Croxall

Smith

Pellegrini

et al. 2017

ApJ

Self Cite

View full text Add to dashboard Cite

The [C II] 158 μm fine-structure line is the brightest emission line observed in local star-forming galaxies. As a major coolant of the gas-phase interstellar medium, [C II] balances the heating, including that due to far-ultraviolet photons, which heat the gas via the photoelectric effect. However, the origin of [C II] emission remains unclear because C + can be found in multiple phases of the interstellar medium. Here we measure the fractions of [C II] emission originating in the ionized and neutral gas phases of a sample of nearby galaxies. We use the [N II] 205 μm fine-structure line to trace the ionized medium, thereby eliminating the strong density dependence that exists in the ratio of emission originates from neutral gas. We find that the fraction of [C II] originating in the neutral medium has a weak dependence on dust temperature and the surface density of star formation, and has a stronger dependence on the gas-phase metallicity. In metal-rich environments, the relatively cooler ionized gas makes substantially larger contributions to total [C II] emission than at low abundance, contrary to prior expectations. Approximate calibrations of this metallicity trend are provided.

show abstract

Section: Pacs Photometry and Spectroscopymentioning

confidence: 99%

The Origins of [C ii] Emission in Local Star-forming Galaxies

Croxall

Smith

Pellegrini

et al. 2017

ApJ

Self Cite

View full text Add to dashboard Cite

show abstract

“…They span a range in total infrared (TIR) luminosity of L TIR ∼ 10 8.3 − 10 10.7 L ⊙ (Dale et al 2012) and in distance of D ∼ 2.8 − 26.5 Mpc. Their metallicities, taken from Moustakas et al (2010) and measured as the average between the characteristic oxygen abundances from the Pilyugin & Thuan (2005) (PT05) and Kobulnicky & Kewley (2004) (KK04) calibrations (Croxall et al 2013), are in the 12+log(O/H) ∼ 8.1−9.0 range.…”

Section: Main Sample Descriptionmentioning

confidence: 99%

Thermal Pressure in the Cold Neutral Medium of Nearby Galaxies

Herrera-Camus

Bolatto

Wolfire

et al. 2017

ApJ

Self Cite

View full text Add to dashboard Cite

Dynamic and thermal processes regulate the structure of the multi-phase interstellar medium (ISM), and ultimately establish how galaxies evolve through star formation. Thus, to constrain ISM models and better understand the interplay of these processes, it is of great interest to measure the thermal pressure (P th ) of the diffuse, neutral gas. By combining [C II] 158 µm, HI, and CO data from 31 galaxies selected from the Herschel KINGFISH sample, we have measured thermal pressures in 534 predominantly atomic regions with typical sizes of ∼1 kiloparsec. We find a distribution of thermal pressures in the P th /k ∼ 10 3 − 10 5 K cm −3 range. For a sub-sample of regions with conditions similar to those of the diffuse, neutral gas in the Galactic plane, we find thermal pressures that follow a log-normal distribution with a median value of P th /k ≈ 3600 K cm −3 . These results are consistent with thermal pressure measurements using other observational methods. We find that P th increases with radiation field strength and star formation activity, as expected from the close link between the heating of the gas and the star formation rate. Our thermal pressure measurements fall in the regime where a two-phase ISM with cold and warm neutral medium could exist in pressure equilibrium. Finally, we find that the midplane thermal pressure of the diffuse gas is about ∼ 30% of the vertical weight of the overlying ISM, consistent with results from hydrodynamical simulations of self-regulated star formation in galactic disks.

show abstract

“…Following Moustakas et al, we use the fitted radial abundance gradients, where available, to compute 12+log(O/H) in each of our regions, and then average the two values obtained using each of the two strong line calibrations the authors chose (a procedure that, for the abundance range in the sample, recovers abundances similar to those measured directly using temperature-sensitive auroral lines; Croxall et al 2013). For the four galaxies studied not available in the Moustakas et al sample, we adopted direct or comparable strong-line abundance values.…”

Section: The Impact Of Metal Abundance On the Deficitmentioning

confidence: 99%

The Spatially Resolved Cooling Line Deficit in Galaxies

Smith

Croxall

Draine

et al. 2016

ApJ

View full text Add to dashboard Cite

We present [C II] 158 μm measurements from over 15,000 resolved regions within 54 nearby galaxies of the KINGFISH program to investigate the so-called [C II] "line-cooling deficit" long known to occur in galaxies with different luminosities. The [C II]/TIR ratio ranges from above 1% to below 0.1% in the sample, with a mean value of 0.48±0.21%. We find that the surface density of 24 μm emission dominates this trend, with [C II]/TIR dropping as n m n I 24 m ( )increases. Deviations from this overall decline are correlated with changes in the gas-phase metal abundance, with higher metallicity associated with deeper deficits at a fixed surface brightness. We supplement the local sample with resolved [C II] measurements from nearby luminous infrared galaxies and highredshift sources from z=1.8-6.4, and find that star formation rate density drives a continuous trend of deepening [C II] deficit across six orders of magnitude in S SFR . The tightness of this correlation suggests that an approximate S SFR can be estimated directly from global measurements of [C II]/TIR, and a relation is provided to do so. Several low-luminosity active galactic nucleus (AGN) hosts in the sample show additional and significant central suppression of [C II]/TIR, but these deficit enhancements occur not in those AGNs with the highest X-ray luminosities, but instead those with the highest central starlight intensities. Taken together, these results demonstrate that the [C II] line-cooling line deficit in galaxies likely arises from local physical phenomena in interstellar gas.

show abstract

Toward a Removal of Temperature Dependencies From Abundance Determinations: NGC 628

Cited by 40 publications

References 50 publications

The Origins of [C ii] Emission in Local Star-forming Galaxies

The Origins of [C ii] Emission in Local Star-forming Galaxies

Thermal Pressure in the Cold Neutral Medium of Nearby Galaxies

The Spatially Resolved Cooling Line Deficit in Galaxies

Contact Info

Product

Resources

About