Large-Scale Expansion in the Carina Nebula

Huchtmeier, W. K.; Day, G. A.

doi:10.1007/978-94-010-2263-7_27

Cited by 13 publications

(26 citation statements)

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“…Huchtmeier & Day (1975) 1975) in equation (9), we obtain CHα,NII = 4.0 × 10 −3 for both Nagao et al 2012). It is interesting to point out that we obtained the same value of CHα,NII for both Carina I and Carina II; indeed, Oberst et al (2011) show that they have similar gas density and radiation field intensity from line ratio analysis (see their figure 17).…”

Section: The Diffuse Ism: Moleculessupporting

confidence: 68%

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First-generation science cases for ground-based terahertz telescopes

Hirashita

Koch

Matsushita

et al. 2015

Publications of the Astronomical Society of Japan

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Ground-based observations at terahertz (THz) frequencies are a newly explorable area of astronomy for the next ten years. We discuss science cases for a first-generation 10-m class THz telescope, focusing on the Greenland Telescope as an example of such a facility. We propose science cases and provide quantitative estimates for each case. The largest advantage of ground-based THz telescopes is their higher angular resolution (∼ 4 arcsec for a 10-m dish), as compared to space or airborne THz telescopes. Thus, high-resolution mapping is an important scientific argument. In particular, we can isolate zones of interest for Galactic and extragalactic star-forming regions. The THz windows are suitable for observations of high-excitation CO lines and [N II] 205 µm lines, which are scientifically relevant tracers of star formation and stellar feedback. Those lines are the brightest lines in the THz windows, so that they are suitable for the initiation of ground-based THz observations. THz polarization of star-forming regions can also be explored since it traces the dust population contributing to the THz spectral peak. For survey-type observations, we focus on "sub-THz" extragalactic surveys, whose uniqueness is to detect galaxies at redshifts z ∼ 1-2, where the dust emission per comoving volume is the largest in the history of the Universe. Finally we explore possibilities of flexible time scheduling, which enables us to monitor active galactic nuclei, and to target gamma-ray burst afterglows. c 2014. Astronomical Society of Japan. 2Publications of the Astronomical Society of Japan, (2014), Vol. 00, No. 0 For these objects, THz and submillimeter wavelength ranges have not yet been explored.

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Section: The Diffuse Ism: Moleculessupporting

confidence: 68%

“…Multiplying the intensity with the consistent area with radio observations by Huchtmeier & Day (1975), that is, 4. ′ 5 × 6.…”

Section: The Diffuse Ism: Moleculesmentioning

confidence: 99%

First-generation science cases for ground-based terahertz telescopes

Hirashita

Koch

Matsushita

et al. 2015

Publications of the Astronomical Society of Japan

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“…6. Data points from the literature are as for G267.9−1.1 where data are available with the addition of 1.4 GHz (Retallack 1983), 8.9 GHz (Huchtmeier & Day 1975) and 22 GHz (Tateyama et al 1991). We re‐analysed the Parkes 5‐GHz map of Haynes et al (1978) and found it to be consistent with the Goss & Shaver (1970) result.…”

Section: Resultsmentioning

confidence: 99%

CBI limits on 31 GHz excess emission in southern H II regions

Dickinson

Davies

Bronfman

et al. 2007

Monthly Notices of the Royal Astronomical Society

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We have mapped four regions of the southern Galactic plane at 31 GHz with the Cosmic Background Imager. From the maps, we have extracted the flux densities for six of the brightest H ii regions in the southern sky and compared them with multifrequency data from the literature. The fitted spectral index for each source was found to be close to the theoretical value expected for optically thin free–free emission, thus confirming that the majority of flux at 31 GHz is due to free–free emission from ionized gas with an electron temperature of ≈7000–8000 K. We also found that, for all six sources, the 31‐GHz flux density was slightly higher than the predicted value from data in the literature. This excess emission could be due to spinning dust or another emission mechanism. Comparisons with 100‐μm data indicate an average dust emissivity of 3.3 ± 1.7 μK (MJy sr−1)−1, or a 95 per cent confidence limit of <6.1 μK (MJy sr−1)−1. This is lower than that found in diffuse clouds at high Galactic latitudes by a factor of ∼3–4. The most significant detection (3.3σ) was found in G284.3−0.3 (RCW 49) and may account for up to ≈30 per cent of the total flux density observed at 31 GHz. Here, the dust emissivity of the excess emission is 13.6 ± 4.2 μK (MJy sr−1)−1 and is within the range observed at high Galactic latitudes. Low‐level polarized emission was observed in all six sources with polarization fractions in the range 0.3–0.6 per cent. This is likely to be mainly due to instrumental leakage and is therefore an upper limit to the free–free polarization. It corresponds to an upper limit of ∼1 per cent for the polarization of anomalous emission.

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“…Radio recombination‐line observations of the ionized gas in this region (Car II) reveal a complex velocity structure which has been interpreted as an expanding shell centred close to η Car (Huchtmeier & Day 1975; Deharveng & Maucherat 1975). There are two main velocity components, the relative fluxes of which vary across the region; one having LSR velocities between −6 and −17 km s −1 and the other having LSR velocities between −23 and −41 km s −1 .…”

Section: Discussionmentioning

confidence: 99%

Unlocking the Keyhole: H2 and PAH emission from molecular clumps in the Keyhole Nebula

Brooks

Burton

Rathborne

et al. 2002

Monthly Notices of the Royal Astronomical Society

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To better understand the environment surrounding CO emission clumps in the Keyhole Nebula, we have made images of the region in H2 1–0 S(1) (2.122‐μm) emission and polycyclic aromatic hydrocarbon (PAH) emission at 3.29 μm. Our results show that the H2 and PAH emission regions are morphologically similar, existing as several clumps, all of which correspond to CO emission clumps and dark optical features. The emission confirms the existence of photodissociation regions (PDRs) on the surface of the clumps. By comparing the velocity range of the CO emission with the optical appearance of the H2 and PAH emission, we present a model of the Keyhole Nebula whereby the most negative velocity clumps are in front of the ionization region, the clumps at intermediate velocities are in it and those which have the least negative velocities are at the far side. It may be that these clumps, which appear to have been swept up from molecular gas by the stellar winds from η Car, are now being overrun by the ionization region and forming PDRs on their surfaces. These clumps comprise the last remnants of the ambient molecular cloud around η Car.

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Large-Scale Expansion in the Carina Nebula

Cited by 13 publications

References 0 publications

First-generation science cases for ground-based terahertz telescopes

First-generation science cases for ground-based terahertz telescopes

CBI limits on 31 GHz excess emission in southern H II regions

Unlocking the Keyhole: H2 and PAH emission from molecular clumps in the Keyhole Nebula

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