1 / 21

STUDYING THE FAST WIND IN PPNs VIA H 2 Bruce J. Hrivnak (Valparaiso University, USA)

STUDYING THE FAST WIND IN PPNs VIA H 2 Bruce J. Hrivnak (Valparaiso University, USA). Doug Kelly, Kate Su (U. Arizona) Sun Kwok (U. Calgary) Ken Hinkle (NOAO) Raghavendra Sahai (JPL). Why? Surveys to identify H 2 in PPNs --> correlations? --> mechanisms?

taniel
Télécharger la présentation

STUDYING THE FAST WIND IN PPNs VIA H 2 Bruce J. Hrivnak (Valparaiso University, USA)

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. STUDYING THE FAST WIND IN PPNs VIA H2 • Bruce J. Hrivnak (Valparaiso University, USA) Doug Kelly, Kate Su (U. Arizona) Sun Kwok (U. Calgary) Ken Hinkle (NOAO) Raghavendra Sahai (JPL) • Why? • Surveys to identify H2 in PPNs • --> correlations? • --> mechanisms? • Spatial imaging of H2 • --> location of the emission? • Model of Evolution • Kinematics Egg Nebula (Sahai et al. 1998) H2(red), 1.6 mm(green), 0.6mm(blue) APN3: (Mt. Rainier 2003-07)

  2. INTRODUCTION: Why study H2 in PPNs? Shaping of PNs: Substantial shaping occurs early in the PPN phase (or even at the end of the AGB phase). Factors to investigate: - variation of density with latitude in CSE – circumstellar disks - variation of mass loss with latitude - initiation of fast wind, which shapes the density variation • How to investigate the initiation of the fast wind? • - extended wings in CO millimeter-line observations (+/- 100 km/s) • - extended wings in Ha emission • - H2 emission • H2 signature of fast wind: • - collisional excitation - shocks at interaction with AGB remnant • - location at the ends of lobes, away from star • - kinematics of H2emission

  3. SURVEYS TO IDENTIFY H2 IN PPNs: Kelly & Hrivnak (in prep): (+ other studies, discuss shortly) Steward Obs. 2.3-m telescope with FSpec, R~2600 2.10 - 2.35 mm {1-0 S(1), 1-0 S(0), 2-1 S(1), 2-1 S(2), 3-2 S(3)} Detected H2 in 15/50 sources (12 new detections) (1) F-G stars: 7/30 5 are bipolar (with optically-thick regions) (2) B star: 7/8 (+ 1 very young PN) 1-0 S(1) 1-0 S(0) 2-1 S(1)

  4. B PN F B B1 B G2 B B G HII

  5. SURVEYS: Correlations with properties +Garcia-Hernandez et al. 2002 (SH); Weintraub et al. 1998; AFGL 618, 2688 (+10/30 sources) 0/7 7/36 1/6 13/15 Kelly & Hrivnak (15/50 sources, NH) Spectral Type: - M: 0/3 - F-G: 6/30 - A: 0/5 - B: 7/8 Morphology: - F-G: bipolar (optically-thick) 4/4 bipolar (optically-thin) 0/3 unknown: 2/2 non-bipolar* 0/21 - B: bipolar 0/0 non-bipolar 7/8 5/5 0/4 2/2 0/25 2/2 11/13 Galactic Latitudes: - F-G: with H2 3.6 (±1.2, n=5) - F-G: without H2 8.2 (±1.5, 24) - B: with H2 8.1 (±2.4, 7) 3.6 (±1.0, 7) 8 (±1, 29) 7.0 (±1.4, 13) * Detection limit compromised by contrast effect in non-bipolars with bright stellar continuum. Note: Garcia-Hernandez et al. found similar results for spectral type correlation.

  6. SURVEYS TO IDENTIFY H2 IN PPNs: • Excitation Mechanism? • Ratio H2 1-0 S(1)/2-1 S(1) • > 10  collisional ex. IRAS 17150-3224 (G2) • 1.3-2.0  radiative ex. IRAS 20462+3416 (B1) • v > 2  radiative all the B stars + results of morphological correlations Results for PPNs with H2: F-G stars: primarily collisional, associated with bipolar shape B stars: primarily radiative, apparently not assoc. with bipolar shape Most are some mixture of collisional and radiative Van de Steene & van Hoof (2003) - Careful study of IRAS 16594-4656 including additional H2 lines; indicates mainly collisional excitation and they also discusses types of shocks.

  7. SPATIAL IMAGING OF PPNs: Egg Nebula (Sahai et al. 1998) – F5 (collisional) Location of H2 Rob 22 (A) (rad +?) Hen 3-401 (B) (collisional) Sahai et al. 1999, APNII Conf.

  8. SPATIAL IMAGING OF PPNs: IRAS 17150-3224 - G2 (collisional) H2 H2(red), I(green), V(blue) V Location of H2: primarily at ends of lobes - clumps, faint loop (skirt) around equator.

  9. IRAS 17441-2411 1” V H2 J (1.2 mm) V H (1.6 mm) H2 1”

  10. IRAS 16594-4656 2” H2 J V IRAS 18379-1707 H2 H (1.6 mm) 1”

  11. MODEL OF EVOLUTION: B* bipolar H2 in lobes col + rad G* bipolar H2 in lobes collisional PN bipolar H2 in disk collisional higher-M progenitor B* non-bipolar H2 near star radiative G* elliptical no H2 PN non-bipolar no H2 lower-M progenitor Similar scenario by Garcia-Hernandez et al. (2002)

  12. KINEMATICS: AFGL 2688, 618 – Kastner et al. (2001) – high resolution Phoenix observations

  13. KINEMATICS: AFGL 2688, 618 – Kastner et al. (2001) • deceleration of outflow along the bipolar axis in Egg Nebula, AFGL 618.

  14. KINEMATICS: Work in Progress IRAS 17150-3224 Phoenix on 4-m KPNO (G2) | slit along major axis  (continuum-subtracted) Lobes: DV = 40 km/s Center: split into blue and red, width = 10 km/s (see Kelly poster for more details)

  15. KINEMATICS: Work in Progress Phoenix on 8-m Gemini-S Rob 22 (SpT=A) slit along major axis • IRAS 19306+1407 (B) • med-res spectrum indicates both • collisional and radiative excitation. • high-res spectrum (right) shows • (a) knot from center, blue-shifted, • width = 10 km/s • (b) extended region, width = 60 km/s (continuum-subtracted)

  16. H2 IN PPNs: SUMMARY • H2 is common in bipolar F-G PPNs with optically-thick torus • - shock excited • - occurs in lobes, near ends • - not seen in non-bipolar F-G PPNs •  fast wind beginning in SpT=G, but not earlier • (2) H2 is universal(?) in B PPNs, irrespective of morphology • - mostly radiatively excited •  phase that all PPNs go through prior to photo-dissociation • of H2 and photo-ionization of nebula (PN) • (3) High-resolution spectra now becoming available to study the • kinematics in detail. • - spatial-kinematic studies

  17. Equatorial Structures APNIII - 2003

  18. Shaping: due to fast outflow – can we see the initiation of it? Evidence for a fast outflow seen in extended wings of submm CO lines in a few PPNs: Egg Nebula, AFGL 618, IRAS 19500-1709 Can also look for interaction between fast outflow and AGB remnant. 1-0 S(1) 1-0 S(0) 2-1 S(1) Shocked H2 - Egg Nebula: H2 seen at ends of lobes and ends of obscuring region - IRAS 17150-3224 (below): seen at ends of lobes (HST-NICMOS) High H2 1-0 S(1)/2-1 S(1) ratio indicates collisional excitation

  19. IRAS 18379-1707

More Related