1 / 14

[OI] and [NII] Observations of Relevance to STO

[OI] and [NII] Observations of Relevance to STO. Gordon Stacey. 3 P 2. 188 K. N +. 3 P 1. 70 K. 0 K. 3 P 0. [NII] Lines. Density tracer for low density ionized gas Proxy for Lyman continuum flux Determines [CII] fraction from ionized gas [NII] has two transitions

klaus
Download Presentation

[OI] and [NII] Observations of Relevance to STO

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. [OI] and [NII] Observations of Relevance to STO Gordon Stacey

  2. 3P2 188 K N+ 3P1 70 K 0 K 3P0 [NII] Lines • Density tracer for low density ionized gas • Proxy for Lyman continuum flux • Determines [CII] fraction from ionized gas • [NII] has two transitions • Both these lines relatively unexplored • 122 m line somewhat challenging from airplane • 205 m line at long wavelength end of photoconductors • Lines are strong – fair number of ISO LWS observations of 122 m line • 2 KAO observations using the CGS of both lines (M82 and G333.6-0.2) • Large beam COBE observations of 205 m line • Ground based 205 m line observations 122 um 205 um

  3. 3P0 327 K O0 3P1 228 K 0 K 3P2 [OI] Lines • Many observations of these lines from Galactic and extra-galactic sources • KAO/ISO LWS • Very strong lines in general • [OI]/[CII] typically ½ • [OI] 63/146 ~ 15-20:1 146 um 63 um

  4. COBE • Large (7.2) beam • What is the scale height? • PDR or ionized gas • [CII]/[NII] 205 ~ 10:1 • [CII]/[NII] 122 ~ 6:1 • Argue for 27% of [CII] from ionized gas

  5. [NII] 205 m Line: Carina Nebula • [NII] 205 m line from in the Carina Nebula with SPIFI on AST/RO at South Pole (Oberst et al. 2006) • [NII] 122/205 m line ratio ~ 1.8: 1  ne ~ 30 cm-3 • [CII]/[NII] ratio ~ 9:1, predicted ratio ~ 2.4:1  27% of [CII] originates from ionized gas

  6. Observations of Candidate Sources • M17 KAO: Meixner et al. 1992 • Peak ~ 1.310-3erg/s/cm2/sr • Beam ~ 36” • ISO: Henning et al. 1998 A&A 332, 1035 • Just one spectrum presented • [OI] and [NII] lines detected

  7. Other Candidates • MBM12 – nearby starformation region • Haven’t found much yet – Mark Wolfire found [CII] • Polaris Flare • Again, haven’t found much ISO data yet • Carina Nebula • SPIFI-AST/RO map of [NII] over > 10’ square region with 55” beam • ISO [NII] 122 m, [OI] and [CII] data available and published (Mizutani et al. 2002, 2004)

  8. DR21 in Cygnus • KAO [OI] 63 m line obtained over inner 2.5’ (Poglitsch et al. 1996) – 25” beam • ISO LWS spectroscopy available and published in Jakob et al. 2007 including [NII] and [OI] lines

  9. Galactic Plane Surveys • Not really any dedicated surveys in [OI] or [NII] save COBE FIRAS • However there has been work on the ISO data set – collecting all the observations

  10. ISO Study of the Diffuse ISM • Searched the ISO archive and find there are about 500 LO1 spectra of Galactic LOS w/o known energetic sources • LWS01: 47 to 196 m • [OI] 63 and 145 m • [CII] 158 m • [NII] 122 m • Current study contains 144 LOS w/ l <10

  11. Inner Outer 100 um continuum flux (33 Jy) Galactic Center Galactic Longitude (abs. value) Three Regions Defined

  12. Dust color temperature • Plot is 100/160 vs. 62.5/100 continuum ratios • Tracks are grey body temps for  = 0 an 1.5 • Shift below  = 0 is likely due to hot small grain contribution at 63.5 m (40% in inner galaxy and 60% in outer galaxy • Color temps and  need to be corrected for this effect

  13. Atomic Fine Structure Lines • Excellent correlation between the line intensities and far-IR continuum

  14. Larger PDR contribution in brighter regions Not much (1/6) [CII] from ionized gas Optically thick or forground absorbed 63 m line Line Ratios • Low continuum (33 Jy/beam) • [CII]/[NII] ~ 3.6:1 • [OI](63)/[CII] ~ 1:3 • [OI](63)/[OI] 146 ~ 15:1 • High continuum (3300 Jy/beam) • [CII]/[NII] ~ 13:1 • [OI](63)/[CII] ~ 1:2.5 • [OI](63)/[OI] 146 ~ 8.5:1

More Related