Far-infrared mapping of the starburst galaxy NGC 253 with ISOPHOT

Radovich, M.; Kahanpää, Jere; Lemke, D.

doi:10.1051/0004-6361:20011102

Cited by 61 publications

(71 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The dust temperature in the calculation above is from the peak brightness temperature of the 12 CO lines at the continuum sources. It is also consistent, within a factor of two, with the dust temperatures inferred for the nuclear region by fitting the spectral energy distribution (SED) in the far-infrared (Radovich et al 2001;Melo et al 2002;Weiß et al 2008). We did not subtract non-dust emission from the continuum or correct the continuum flux density for missing flux because the two corrections are less than a few 10% each and are in opposite directions.…”

Section: Mass and Column Density From Continuumsupporting

confidence: 80%

“…The warmer gas in NGC 253 is consistent with the larger luminosity of the starburst nucleus and in accordance with the higher dust temperature there. The dust temperature in the Galactic CMZ has been estimated to be ∼20 K from SED fitting in the submillimeter-to-far-infrared bands (Pierce-Price et al 2000, and references therein), while dust in the center of NGC 253 was estimated also from SED fitting to be at or above 30 K (Radovich et al 2001;Melo et al 2002;Weiß et al 2008). The high-temperature gas in the center of NGC 253 has also been pointed out from the line excitation analyses mentioned in Section 3.4.…”

Section: Comparison With the Center Of Our Galaxymentioning

confidence: 99%

See 1 more Smart Citation

Star-Forming Cloud Complexes in the Central Molecular Zone of NGC 253

Sakamoto

Mao

Matsushita

et al. 2011

ApJ

123

View full text Add to dashboard Cite

We report 350 and 230 GHz observations of molecular gas and dust in the starburst nucleus of NGC 253 at 20-40 pc (1 -2 ) resolution. The data contain CO(3-2), HCN(4-3), CO(2-1), 13 CO(2-1), C 18 O(2-1), and continuum at 0.87 mm and 1.3 mm toward the central kiloparsec. The CO(2-1) size of the galaxy's central molecular zone (CMZ) is measured to be about 300 pc × 100 pc at the half-maximum of intensity. Five clumps of dense and warm gas stand out in the CMZ at arcsecond resolution, and they are associated with compact radio sources due to recent massive star formation. They contribute one-third of the CO emission in the central 300 pc and have 12 CO peak brightness temperatures around 50 K, molecular gas column densities on the order of 10 4 M pc −2 , gas masses on the order of 10 7 M in the size scale of 20 pc, volume-averaged gas densities of n H 2 ∼ 4000 cm −3 , and high HCN-to-CO ratios suggestive of higher fractions of dense gas than in the surrounding environment. It is suggested that these are natal molecular cloud complexes of massive star formation. The CMZ of NGC 253 is also compared with that of our Galaxy in CO(2-1) at the same 20 pc resolution. Their overall gas distributions are strikingly similar. The five molecular cloud complexes appear to be akin to such molecular complexes as Sgr A, Sgr B2, Sgr C, and the l = 1.• 3 cloud in the Galactic center. On the other hand, the starburst CMZ in NGC 253 has higher temperatures and higher surface (and presumably volume) densities than its non-starburst cousin.

show abstract

Section: Mass and Column Density From Continuumsupporting

confidence: 80%

Section: Comparison With the Center Of Our Galaxymentioning

confidence: 99%

Star-Forming Cloud Complexes in the Central Molecular Zone of NGC 253

Sakamoto

Mao

Matsushita

et al. 2011

ApJ

123

View full text Add to dashboard Cite

show abstract

“…Our estimate of the intrinsic ER luminosity is somewhat lower than that derived by Soifer et al (2002) and Spoon et al (2004), who found a lower limit of $7 ; 10 10 L , but confirms qualitatively their results. The starburst luminosity in the ER seems to be similar to that of moderately bright infrared galaxies, such as NGC 253 (Radovich et al 2001).…”

Section: II and O Imentioning

confidence: 77%

The Far‐Infrared Spectrum of Arp 220

González-Alfonso

Smith

Fischer

et al. 2004

ApJ

103

119

View full text Add to dashboard Cite

Infrared Space Observatory Long Wavelength Spectrometer grating observations of the ultraluminous infrared galaxy Arp 220 shows absorption in molecular lines of OH, H 2 O, CH, NH, and NH 3 , as well as in the [O i] 63 m line and emission in the [C ii] 158 m line. We have modeled the continuum and the emission/absorption of all observed features by means of a nonlocal radiative transfer code. The continuum from 25 to 1300 m is modeled as a warm (106 K) nuclear region that is optically thick in the far-infrared, attenuated by an extended region (2 00 ) that is heated mainly through absorption of nuclear infrared radiation. The molecular absorption in the nuclear region is characterized by high excitation due to the high-infrared radiation density. The OH column densities are high toward the nucleus (2 6 ; 10 17 cm À2 ) and the extended region ($2 ; 10 17 cm À2 ). The H 2 O column density is also high toward the nucleus (2 10 ; 10 17 cm À2 ) and lower in the extended region. The column densities in a halo that accounts for the absorption in the lowest lying lines are similar to what are found in the diffuse clouds toward the star-forming regions in the Sgr B2 molecular cloud complex near the Galactic center. Most notable are the high column densities found for NH and NH 3 toward the nucleus, with values of $1:5 ; 10 16 cm À2 and $3 ; 10 16 cm À2 , respectively, whereas the NH 2 column density is lower than $2 ; 10 15 cm À2 . A combination of photodissociation regions (PDRs) in the extended region and hot cores with enhanced H 2 O photodissociation and a possible shock contribution in the nuclei may explain the relative column densities of OH and H 2 O, whereas the nitrogen chemistry may be strongly affected by cosmic-ray ionization. The [C ii] 158 m line is well reproduced by our models and its ''deficit'' relative to the C ii/far-IR ratio in normal and starburst galaxies is suggested to be mainly a consequence of the dominant non-PDR component of far-infrared radiation, although our models alone cannot rule out extinction effects in the nuclei.

show abstract

“…These temperature measurements have shown that the dust is warmer in the centers of galaxies than in the outskirts (e.g., Alton et al 1998;Radovich et al 2001;Melo et al 2002;Dupac et al 2003). Cool dust at roughly the same temperature in spiral disks is detected globally at longer wavelengths (850 μm and 1.3 mm; Siebenmorgen et al 1999;Dunne et al 2000Dunne et al , 2001Vlahakis et al 2005), but there is also some evidence of a Herschel is an ESA space observatory with science instruments provided by the European-led Principal Investigator consortia and with important participation from NASA.…”

Section: Introductionmentioning

confidence: 99%

Enhanced dust heating in the bulges of early-type spiral galaxies

Engelbracht¹,

Hunt

Skibba³

et al. 2010

A&A

View full text Add to dashboard Cite

Stellar density and bar strength should affect the temperatures of the cool (T ∼ 20−30 K) dust component in the inner regions of galaxies, which implies that the ratio of temperatures in the circumnuclear regions to the disk should depend on Hubble type. We investigate the differences between cool dust temperatures in the central 3 kpc and disk of 13 nearby galaxies by fitting models to measurements between 70 and 500 μm. We attempt to quantify temperature trends in nearby disk galaxies, with archival data from Spitzer/MIPS and new observations with Herschel/SPIRE, which were acquired during the first phases of the Herschel observations for the KINGFISH (Key Insights on Nearby Galaxies: a Far-Infrared Survey with Herschel) sample. We fit single-temperature modified blackbodies to far-infrared and submillimeter measurements of the central and disk regions of galaxies to determine the temperature of the component(s) emitting at those wavelengths. We present the ratio of central-region-todisk-temperatures of the cool dust component of 13 nearby galaxies as a function of morphological type. We find a significant temperature gradient in the cool dust component in all galaxies, with a mean center-to-disk temperature ratio of 1.15 ± 0.03. The cool dust temperatures in the central ∼3 kpc of nearby galaxies are 23 (±3)% hotter for morphological types earlier than Sc, and only 9 (±3)% hotter for later types. The temperature ratio is also correlated with bar strength, with only strongly barred galaxies having a ratio over 1.2. The strong radiation field in the high stellar density of a galactic bulge tends to heat the cool dust component to higher temperatures, at least in early-type spirals with relatively large bulges, especially when paired with a strong bar.

show abstract

Far-infrared mapping of the starburst galaxy NGC 253 with ISOPHOT

Cited by 61 publications

References 30 publications

Star-Forming Cloud Complexes in the Central Molecular Zone of NGC 253

Star-Forming Cloud Complexes in the Central Molecular Zone of NGC 253

The Far‐Infrared Spectrum of Arp 220

Enhanced dust heating in the bulges of early-type spiral galaxies

Contact Info

Product

Resources

About