1. Late Type stars PACS-ST Workshop, Jan 28/29, 2003, MPE Garching Franz Kerschbaum for the UNIVIE PACS team

2. Late type starsPACS-ST Workshop, Jan. 20032 AGB-Mass Loss Scenario Kolenberg (1998) after Sedlmayr (1990)

3. Late type starsPACS-ST Workshop, Jan. 20033 Fields of special interest Physics/chemistry of the inner parts of nearby circumstellar envelopes (CSE) –chemistry, cooling(, dynamics by HIFI) Mass loss mineralogy Mass loss history –Detailed structure of spatially resolved nearby circumstellar envelopes (supp. by SPIRE) –Surveys for fossile shells in different environments

4. Late type starsPACS-ST Workshop, Jan. 20034 Physics/chemistry of the inner parts of CSEs 2 Molecular transitions sample different parts of CSEs because of different chemistry and excitation requirements CSEs provide wide ranges of density, kin. temperature and radiation environments Example of a 10 -5 M  /yr CSE: CO(1-0) samples typically a radius of 10 17 cm, CO (5-4), (10-9), and (15-14) sample 6  10 15, 2  10 15, and 7  10 14 cm, respectively IRAM PdB

5. Late type starsPACS-ST Workshop, Jan. 20035 Physics/chemistry of the inner parts of CSEs 2 PACS (+SPIRE/HIFI) offer a complete info about the physical conditions of the inner ML zones (e.g. important coolants CO, H 2 O for O-rich and CO and HCN in C-rich CSEs) For low resolution spectra PACS will have a much higher sensitivity than ISO, which was limited to high ML and/or very nearby objects HIFIs high resolution spectra will allow studies of the dynamics of these (partially ML driving) zones Barlow et al. 1997

6. Late type starsPACS-ST Workshop, Jan. 20036 Mass loss mineralogy 1 ISO caused a revolution in the field of astro-mineralogy of both low- and high-MLR objects But most of these findings were in the SWS and not the LWS range! What to expect from PACS? Posch et al. 2002

7. Late type starsPACS-ST Workshop, Jan. 20037 Mass loss mineralogy 2 Features expected: Forsterite (Mg 2 SiO 4 ) at 69  m (sharp, dust thermometer!) Calcite CaCO 3 at 92.6  m Crystalline water-ice at 61  m (broad, high S/N needed) 62-63  m feature (Cands: Dolomite, Ankerite, Diopsid) CaAl 12 O 19 feature at 78  m Most ISO observation were really suffering S/N problems (esp. for the interesting low MLR-objects). The sensitivity of Herschel would be crucial but the short wave-length end of PACS is the clear limitation in this field! Sylvester et al. 1999 Bowey et al. 2002 Kemper 2002

8. Late type starsPACS-ST Workshop, Jan. 20038 Quantitative results: Spectroscopy (for mineralogy) Low/intermediate-MLR objects in the solar neighbourhood: R Cas: 1.5h for 60-130µm at S/N>20 High-MLR objects out to 1 kpc IRC+10216 like: 6h for 60-130µm at S/N>20

9. Late type starsPACS-ST Workshop, Jan. 20039 Mass loss history 1 Currently it is not clear if AGB-ML is mainly a continuous process or episodic on timescales of ~10 3 yrs as a still small number of observations suggest There may be interrelations between the ML history and the ML geometry For Herschel PACS (+SPIRE) two main strategies seem interesting: –Observations of spatially resolved nearby circumstellar envelopes –Surveys for fossile shells in different environments Balick et al. 2000

10. Late type starsPACS-ST Workshop, Jan. 200310 Mass loss history 2 Spatially resolved nearby detached envelopes For the nearest objects PACS (+SPIRE) will deliver the detailed structures of the detached envelopes (resolving timescales of less than 1000 years) Even very low ML episodes should be detectable (incl. ML modulations) At 1 kpc the largest shells are still more or less filling the FOV. PACS will (just) resolve some shells even at GC distances (beam at 85µm)! Izumiura et al. 1997 Olofsson et al. 2000 Sahai et al. 1998

11. Late type starsPACS-ST Workshop, Jan. 200311 Quantitative results: Imaging (resolved) Typ. cases: 75µm, S/N>20rt (h)t10 (h) y. DSO:R Scl (350pc)12"0.070.08 o. DSO:TT Cyg (500pc),35"0.758 The largest objects to expect have sizes of up to 10'! (U Ant (250pc), r=200" SPIRE will allow for a extension towards longer wavelengths.

12. Late type starsPACS-ST Workshop, Jan. 200312 Mass loss history 3 Surveys in different environments PACS will detect most detached shell objects at GC distances PACS (+SPIRE) should reach high ML stars in the MCs The (relatively) large FOVs will allow mini-surveys in areas already covered by ISO at shorter wavelengths (GC, Bulge, LMC, SMC) Combined CC-Diagrams allow to separate cold CSEs from e.g. molecular clouds Such (quite expensive) mini-surveys have a multidisciplinary use! AURA 2000 Cobe 1999

13. Late type starsPACS-ST Workshop, Jan. 200313 Quantitative results: Imaging pointsources 1 75µm 1kpc 110µm 1kpc 170µm 1kpc 75µm 8kpc 110µm 8kpc 170µm 8kpc 75µm 49kpc 110µm 49kpc l. MLR (g Her) 150mJy36mJy3mJy2.4mJy0.6mJy i. MLR (R Cas) 800mJy360mJy90mJy13mJy6mJy1.4mJy0.3mJy0.2mJy h. MLR (IRC+10216) 41Jy8.4Jy0.6Jy650mJy130mJy10mJy17mJy3.5mJy y. DSO (R Scl) 80mJy38mJy10mJy2mJy1mJy o. DSO (TT Cyg) 15mJy19mJy28mJy0.4mJy0.5mJy

14. Late type starsPACS-ST Workshop, Jan. 200314 Quantitative results: Imaging of pointsources 2 75µm 1kpc 110µm 1kpc 170µm 1kpc 75µm 8kpc 110µm 8kpc 170µm 8kpc 75µm 49kpc 110µm 49kpc l MLR (g Her)  0.1h2.3h3h48h i MLR (R Cas)  0.1h  0.6h10h194h h MLR (IRC+10216)  0.1h  0.3h0.13h1.5h y DSO (R Scl)  0.1h0.3h4.4h21h o DSO (TT Cyg)  0.2h175h

15. Late type starsPACS-ST Workshop, Jan. 200315 Quantitative results: Imaging of pointsources 3 "normal" AGB stars feasible only out to GC, and at the shortest wavelengths High-MLR AGB stars relatively easy out to MCs in full PACS range Detached shell objects easy at GC and some possible at MCs at short wavelengths Always only in combination with ISO-Surveys!