1. Markus Nielbock studied physics in Düsseldorf and Bochum
doctorate in Astrophysics 2001 (Ruhr-Universität Bochum)
ESO fellow 2001 – 2003, SEST, La Silla, Chile
post doc in Bochum 2003 – 2006
post doc at MPIA since December 2006
member of Herschel/PACS ICC (Instrument Control Centre)
responsibilities:
instrument commanding
instrument lab and in-flight testing
AOT verification and optimisation
instrument calibration
scientific verification
data reduction optimisation

2. The HERSCHEL Dust Temperature Map of B 68
Markus Nielbock
O. Krause, R. Launhardt, Z. Balog, J. Kainulainen, H. Linz, S. Ragan,
J. Steinacker, A. Stutz, C. Risacher (SRON), Th. Henning
MPIA PSF Group Retreat, Löwenstein, 27 October 2010

3. Barnard 68 starless core in Pipe Nebula (Ophiuchus)
Markus Nielbock – The HERSCHEL Dust Temperature Map of B 68
Snake Nebula
B72
Pipe Nebula
B68
B69
B74
B71
B70

4. Barnard 68 – A few facts prototype starless core distance ca. 100 pc
diameter ca. 6.5 arcmin (40000 AU = 0.2 pc)
mass in literature: 0.7 – 2.1 M⊙
can be described as an isothermal Bonnor-Ebert sphere in hydrostatic equilibrium (Alves et al. 2001)
oscillating (Lada et al. 2003), induced by external pressure (Redman et al. 2006) or core collision (Burkert & Alves 2009)
molecule freeze-out in core centre (Bergin et al. 2002)
Markus Nielbock – The HERSCHEL Dust Temperature Map of B 68

5. Barnard 68 – The data
Markus Nielbock – The HERSCHEL Dust Temperature Map of B 68
Herschel PACS and SPIRE scan maps PACS standard data reduction up to level 1 + Scanamorphos (Roussel 2010) SPIRE standard data reduction + special drift correction (Bendo 2009)
additional (sub)mm continuum data for SED fitting
NIR extinction map (Alves et al. 2001)
CO and N2H+ molecular line data

6. Barnard 68 – Results so far
temperature gradient from 11 to 16 K
peak column density 6.3x1022 cm-2 (averaged over 8'' pixel)
total mass estimates:
2.9 M⊙ for the entire column density map
2.1 M⊙ for AV > 4 (equivalent to Alves et al. 2001)
1.0 M⊙ for dense core (NH > 3x1022 cm-2)
C18O(1-0) depletion hole coincides with dust temperatures below 12 K
and column densities above 5.5x1022 cm-2
Markus Nielbock – The HERSCHEL Dust Temperature Map of B 68

7. Barnard 68 - Outlook Challenges Future Work
investigate influence of different data reduction schemes
improve convolution of data using appropriate PSF models and kernels
estimate background level and its impact on temperature maps
Mad Map Scanamorphos Scanamorphos – Mad Map
Markus Nielbock – The HERSCHEL Dust Temperature Map of B 68
Future Work
include molecule freeze out
derive proper 3D temperature and density distribution
determine dust properties
estimate balance of external and internal heating