THE PHYSICAL CHARACTERISTICS OF THE GAS IN THE DISK OF CENTAURUS A USING THE<i>HERSCHEL SPACE OBSERVATORY</i>

Parkin, T. J.; Wilson, C. D.; Schirm, M. R. P.; Baes, M.; Boquien, M.; Boselli, A.; Cormier, D.; Galametz, M.; Karczewski, O. Ł.; Lebouteiller, V.; Looze, I. De; Madden, S.; Roussel, H.; Smith, M.; Spinoglio, L.

doi:10.1088/0004-637x/787/1/16

Cited by 16 publications

(23 citation statements)

References 80 publications

(185 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Whilst both the number of pixels and their spatial resolution are low, providing only coarse estimates of the local ionised gas contribution to the [C] emission, our values across the disc appear consistent with previous results from a variety of astronomical sources (see e.g. Oberst et al 2006Oberst et al , 2011Croxall et al 2012;Parkin et al 2013Parkin et al , 2014Farrah et al 2013). The small number of low resolution pixels available when using the [N] 205 µm map introduces a problematic limitation to our analysis, particularly evident when we attempt to use these results to correct our observed [C] emission for the contribution arising from ionised gas in order to facilitate a comparison with the Kaufman et al (1999Kaufman et al ( , 2006) PDR model (Sect.…”

Section: Ionised Gas Contribution To [Cii] Emissionsupporting

confidence: 89%

“…we only observe about half of the total [O] 63 µm emission from all PDRs within the PACS beam, Parkin et al (2013Parkin et al ( , 2014 multiply their observed [O] 63 µm emission by a factor of two. This is a conservative correction; Stacey et al (2010) reason that the observed [O] line intensity should be corrected for these geometric issues by as much as a factor of four for high optical depth in a spherical cloud geometry.…”

Section: Adjustments To Observed Quantitiesmentioning

confidence: 85%

“…In Fig. 7 of Parkin et al (2014), the theoretical line ratios are plotted as a function of stellar temperature for various gas densities as predicted from the H region models of Rubin (1985). ratios we measure across the disc correspond to a range of stellar effective temperatures of approximately 3.43 × 10 4 and 3.65 × 10 4 K, which in turn correspond to stellar classifications of O9 to O9.5 for the most luminous stars (see Fig.…”

Section: Ionised Gas Characteristicsmentioning

confidence: 95%

“…A proper comparison to the PDR model of Kaufman et al (1999Kaufman et al ( , 2006 requires us to make three adjustments to our observed quantities, for which we initially follow the strategy of Parkin et al (2013Parkin et al ( , 2014. Firstly, the observed total infrared flux from extragalactic sources must be reduced by a factor of two in order to account for the optically thin infrared continuum flux emitting not just towards the observer but from both sides of the PDR slab.…”

Section: Adjustments To Observed Quantitiesmentioning

confidence: 99%

“…For example, Croxall et al (2012) studied a late-type spiral, NGC 1097, and a Seyfert 1 galaxy, NGC 4559, finding 50 ≤ G 0 ≤ 1000 varying with 10 2.5 cm −3 ≤ n ≤ 10 3 cm −3 across both discs. Most recently, Parkin et al (2013) examined the n and G 0 in various regions of M 51; the hydrogen density and FUV radiation peak in the nucleus and similarly decline in both the spiral arm and interarm regions, suggesting similar physical conditions in clouds in these environments (see also Parkin et al 2014). …”

Section: Introductionmentioning

confidence: 96%

See 4 more Smart Citations

Insights into gas heating and cooling in the disc of NGC 891 fromHerschelfar-infrared spectroscopy

Hughes

Foyle

Schirm

et al. 2015

A&A

Self Cite

View full text Add to dashboard Cite

We present Herschel PACS and SPIRE spectroscopy of the most important far-infrared cooling lines in the nearby, edge-on spiral galaxy, NGC 891: [C] with increasing FIR colour suggests that polycyclic aromatic hydrocarbons (PAHs) may become important for gas heating in the central regions. We compare the observed flux of the FIR cooling lines and total IR emission with the predicted flux from a PDR model to determine the gas density, surface temperature and the strength of the incident far-ultraviolet (FUV) radiation field, G 0 . Resolving details on physical scales of ∼0.6 kpc, a pixel-by-pixel analysis reveals that the majority of the PDRs in NGC 891's disc have hydrogen densities of 1 < log(n/cm −3 ) < 3.5 experiencing an incident FUV radiation field with strengths of 1.7 < log G 0 < 3. Although these values we derive for most of the disc are consistent with the gas properties found in PDRs in the spiral arms and inter-arm regions of M 51, observed radial trends in n and G 0 are shown to be sensitive to varying optical thickness in the lines, demonstrating the importance of accurately accounting for optical depth effects when interpreting observations of high inclination systems. Increasing the coverage of our analysis by using an empirical relationship between the MIPS 24 µm and [N] 205 µm emission, we estimate an enhancement of the FUV radiation field strength in the far north-eastern side of the disc relative to the rest of the disc that coincides with the above-average star formation rate surface densities and gas-to-dust ratios. However, an accurate interpretation remains difficult due to optical depth effects, confusion along the line-of-sight and observational uncertainties.

show abstract

Section: Ionised Gas Contribution To [Cii] Emissionsupporting

confidence: 89%

Section: Adjustments To Observed Quantitiesmentioning

confidence: 85%

Section: Ionised Gas Characteristicsmentioning

confidence: 95%

Section: Adjustments To Observed Quantitiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

See 3 more Smart Citations

Insights into gas heating and cooling in the disc of NGC 891 fromHerschelfar-infrared spectroscopy

Hughes

Foyle

Schirm

et al. 2015

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

Heating and cooling of the neutral ISM in the NGC 4736 circumnuclear ring

Laan

Armus

Beirão

et al. 2015

A&A

Self Cite

View full text Add to dashboard Cite

The manner in which gas accretes and orbits within circumnuclear rings has direct implications for the star formation process. In particular, gas may be compressed and shocked at the inflow points, resulting in bursts of star formation at these locations. Afterwards the gas and young stars move together through the ring. In addition, star formation may occur throughout the ring, if and when the gas reaches sufficient density to collapse under gravity. These two scenarios for star formation in rings are often referred to as the "pearlson-a-string" and "popcorn" paradigms. In this paper, we use new Herschel/PACS observations, obtained as part of the KINGFISH open time key program, along with archival Spitzer and ground-based observations from the SINGS Legacy project, to investigate the heating and cooling of the interstellar medium in the nearby star-forming ring galaxy, NGC 4736. By comparing spatially resolved estimates of the stellar far-ultraviolet flux available for heating, with the gas and dust cooling derived from the far-infrared continuum and line emission, we show that while star formation is indeed dominant at the inflow points in NGC 4736, additional star formation is needed to balance the gas heating and cooling throughout the ring. This additional component most likely arises from the general increase in gas density in the ring over its lifetime. Our data provide strong evidence, therefore, for a combination of the two paradigms for star formation in the ring in NGC 4736.

show abstract

The spatially resolved correlation between [NII] 205μm line emission and the 24μm continuum in nearby galaxies

Hughes

Baes

Schirm

et al. 2016

A&A

Self Cite

View full text Add to dashboard Cite

A correlation between the 24 µm continuum and the [N] 205 µm line emission may arise if both quantities trace the star formation activity on spatially-resolved scales within a galaxy, yet has so far only been observed in the nearby edge-on spiral galaxy NGC 891. We therefore assess whether the [N] 205−24 µm emission correlation has some physical origin or is merely an artefact of line-ofsight projection effects in an edge-on disc. We search for the presence of a correlation in Herschel and Spitzer observations of two nearby face-on galaxies, M 51 and M 83, and the interacting Antennae galaxies NGC 4038 and 4039. We show that not only is this empirical relationship also observed in face-on galaxies, but also that the correlation appears to be governed by the star formation rate (SFR). Both the nuclear starburst in M 83 and the merger-induced star formation in NGC 4038/9 exhibit less [N] emission per unit SFR surface density than the normal star-forming discs. These regions of intense star formation exhibit stronger ionization parameters, as traced by the 70/160 µm far-infrared (FIR) colour. These observations suggest the presence of higher ionization lines that may become more important for gas cooling, thereby reducing the observed [N] 205 µm line emission in regions with higher star formation rates. Finally, we present a general relation between the [N] 205 µm line flux density and SFR density for normal star-forming galaxies, yet note that future studies should extend this analysis by including observations with wider spatial coverage for a larger sample of galaxies.

show abstract

THE PHYSICAL CHARACTERISTICS OF THE GAS IN THE DISK OF CENTAURUS A USING THEHERSCHEL SPACE OBSERVATORY

Cited by 16 publications

References 80 publications

Insights into gas heating and cooling in the disc of NGC 891 fromHerschelfar-infrared spectroscopy

Insights into gas heating and cooling in the disc of NGC 891 fromHerschelfar-infrared spectroscopy

Heating and cooling of the neutral ISM in the NGC 4736 circumnuclear ring

The spatially resolved correlation between [NII] 205μm line emission and the 24μm continuum in nearby galaxies

Contact Info

Product

Resources

About