Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19...
Transcript of Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19...
![Page 1: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/1.jpg)
By Bavo Croiset
Supervisors: A.G.G.M. Tielens,
O. Berné,
A. Candian
Mapping PAH sizes in
NGC 7023 with SOFIA
![Page 2: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/2.jpg)
Overview
• Introduction
• NGC 7023
• Instruments
• Images
• PAH size emission model
Croiset et al., 2016 , A&A, 590, A26
Bavo Croiset SOFIA Tele-Talk 14-9-2016 2
![Page 3: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/3.jpg)
PAH emission
Tielens (2008)
3Bavo Croiset SOFIA Tele-Talk 14-9-2016
• Polycyclic Aromatic Hydrocarbon
![Page 4: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/4.jpg)
PAH emission“11.2/3.3 µm proportional to PAH size”
• Absorption UV
• Vibrational emission
• Typical vibrational modes:
- C-H 3.3 µm, neutral (stretch)
- C-H 8.6 µm, ionized (in plane bending)
- C-H 11.2 µm, (out of plane bending)
4Bavo Croiset SOFIA Tele-Talk 14-9-2016
Leger, d’Hendecourt, Defourneau (1989)
![Page 5: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/5.jpg)
Photo Dissociation Region
Tielens & Hollenbach (1985)
5Bavo Croiset SOFIA Tele-Talk 14-9-2016
![Page 6: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/6.jpg)
Photo Dissociation Region
Andrews et al., (2015)
6Bavo Croiset SOFIA Tele-Talk 14-9-2016
unstable VSG evaporate → compact PAH at PDR surface
→ PAH broken down
Cavity PDR Molecular cloud
![Page 7: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/7.jpg)
NGC 7023 (Iris nebula)• Reflection Nebula
• Distance: 320 pc
• Herbig Be Star system
Hubble NGC 7023 North PDR (1995)
Stars
7Bavo Croiset SOFIA Tele-Talk 14-9-2016
![Page 8: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/8.jpg)
NGC 7023 (Iris nebula)
Hubble NGC 7023 (1995) & CFHT 2.12 µm
Star
“𝐻2 2.12 µm traces the PDR surface”
8Bavo Croiset SOFIA Tele-Talk 14-9-2016
![Page 9: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/9.jpg)
Instruments
NASA SOFIA
-FLITECAM: 3.3 µm
-FORCAST: 11.2 µm
NASA SPITZER
-IRAC 8.0 µm
CFHT
-MIDAS: 2.12 µm
NASA HST
-NICMOS: ERE
9Bavo Croiset SOFIA Tele-Talk 14-9-2016
![Page 10: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/10.jpg)
AKARI, Pilleri et al., 2015
10Bavo Croiset SOFIA Tele-Talk 14-9-2016
Aliphatic C-H Aromatic C-H
Instruments
![Page 11: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/11.jpg)
Images
Croiset et al., 201611Bavo Croiset SOFIA Tele-Talk 14-9-2016
![Page 12: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/12.jpg)
Images SOFIA
North PDR
South PDR
Croiset et al., 2016 12Bavo Croiset SOFIA Tele-Talk 14-9-2016
Star
![Page 13: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/13.jpg)
Images
PAH
Very Small Grains
13Bavo Croiset SOFIA Tele-Talk 14-9-2016Croiset et al., 2016
![Page 14: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/14.jpg)
PAH emission-size model
• NASA Ames PAH IR spectral database
• Spectra of 27 different PAHs
“Avg. photon energy emitted → Dust extinction
→ absorbed by PAH → PAH spectra → 11.2/3.3 µm”
14Bavo Croiset SOFIA Tele-Talk 14-9-2016
Extinction
Crossection PAH Avg. photon energy absorbed by the PAH
Photon energy emitted
![Page 15: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/15.jpg)
PAH emission-size model
“Avg. photon energy emitted → Dust extinction
→ absorbed by PAH → PAH spectra → 11.2/3.3 µm”
15Bavo Croiset SOFIA Tele-Talk 14-9-2016
![Page 16: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/16.jpg)
PAH emission-size model
Croiset et al., 2016
16Bavo Croiset SOFIA Tele-Talk 14-9-2016
![Page 17: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/17.jpg)
PAH emission-size model
17Bavo Croiset SOFIA Tele-Talk 14-9-2016
![Page 18: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/18.jpg)
PAH emission-size model
18Bavo Croiset SOFIA Tele-Talk 14-9-2016
![Page 19: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/19.jpg)
Summary
• The PDR surface is well traced by the 11.2/3.3 ratio and H2
• A factor of ~2 in size variation
• unstable VSG evaporate → compact PAH at PDR surface
→ smallest PAH broken down → Avg. size increases in the
cavity
Croiset et al., 2016 , A&A, 590, A26
19Bavo Croiset SOFIA Tele-Talk 14-9-2016
![Page 20: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/20.jpg)
Future work
• Observe more objects with SOFIA
• Laboratory work to examine the 11.2/3.3 µm
• Model the effect PAH size in PDR models
• JWST
Croiset et al., 2016 , A&A, 590, A26
20Bavo Croiset SOFIA Tele-Talk 14-9-2016
![Page 21: Mapping PAH sizes in NGC 7023 with SOFIA...2016/09/14 · Bavo Croiset SOFIA Tele-Talk 14-9-2016 19 Future work • Observe more objects with SOFIA • Laboratory work to examine](https://reader036.fdocuments.es/reader036/viewer/2022071212/60255f02a422ab55eb1f94bd/html5/thumbnails/21.jpg)
Images
SOFIA SOFIASpitzer IRAC
21Bavo Croiset SOFIA Tele-Talk 14-9-2016