1. APN III 29 July 2003 William B. Latter SIRTF Science Center and California Institute of Technology

2. 29 July 2003 Latter: APN3-2 Outline  Overview of NGC 7027  NGC 7027 as a carbon-rich photodissociation region (PDR)  Summary of some recent ground- and space-based observations NGC 7027 is among the most observed objects in the sky – both as a standard calibrator object and as a prototypical young planetary nebula. The wealth of data of this object is both remarkable and extraordinary.

3. 29 July 2003 Latter: APN3-3 NGC 7027 Central Star Properties Coordinates (J2000)21h 7m 1.83s/+42 O 14’ 9.93” Zanstra Temperature198100 +/- 10500 K Luminosity (D=880pc)7710 +/- 860 L ⊙ Radius5.21 x 10 9 cm Core mass0.7 M ⊙ Initial Mass4 M ⊙ Evolutionary timescale700 yr from Latter et al. 2000, ApJ, 539, 783

4. 29 July 2003 Latter: APN3-4 Photodissociation Region Schematic (O-rich vs. C-rich) CO + C/C 2 HCO + C2H2C2H2 CN HCN

5. 29 July 2003 Latter: APN3-5 NGC 7027 HST/NICMOS -- The PDR Revealed

6. 29 July 2003 Latter: APN3-6 Two components of a three component model of the emission regions Latter et al. 2000, ApJ, 539, 783

7. 29 July 2003 Latter: APN3-7 See also Latter et al. 2000, ApJ, 539, 783

8. 29 July 2003 Latter: APN3-8 C-rich PDR Models and ISO Observed Infrared Emission Lines NGC7027 Rotational CO emission detected using ISO-LWS Justtanont et al. 2000, A&A, 360, 1117 See also: Fong et al. 2001, A&A, 367, p. 652 and p. 674

9. 29 July 2003 Latter: APN3-9 High resolution near-IR spectro-imaging Cox et al. 2002, A&A, 384, 603 CFHT and Bear ** See poster: D. Mekarnia ** Molecular hydrogen emission @ 2.121 microns

10. 29 July 2003 Latter: APN3-10 Chandra NGC 7027 Data Kastner et al. 2002, ApJ, 581, 1225 See also Maness et al. 2003, ApJ, 589, 439 and refs therein

11. 29 July 2003 Latter: APN3-11 NGC 7027 at Radio Wavelengths Bains et al. 2003, MNRAS, 340, 381 18 cm continuum (L-band) = contours 6 cm continuum (C-band) = greyscale

12. 29 July 2003 Latter: APN3-12 PDR and Wind Evolution in NGC 7027 There is now direct observational confirmation that the molecular hydrogen emission from NGC 7027 is PDR emission, as well as other definite PDR tracers detected, including CO +.  Steady state, plane parallel and more complex models of C-rich PDR reproduce the NGC 7027 chemical properties reasonably well.  The PDR in NGC 7027 is at least 600 years old, with the star having begun evolution off the AGB about 1000 years ago.  The NGC 7027 CSE is not spherically symmetric and is highly non- uniform. Very dense from heavy mass loss from massive progenitor (about 4 M ⊙ ).  There is clear evidence in multiple tracers form the effects of two or more jets or jet-like flows that have disrupted the surrounding nebula. The jets themselves have not been seen, and might have shut down.

13. 29 July 2003 Latter: APN3-13 HST/STIS Observations Bieging et al. in preparation

14. 29 July 2003 Latter: APN3-14 HST/STIS Data (example) Bieging et al. in preparation 52” x 0.1” slits x 5 G430L and G750L gratings