| 1. |
- Aad, G., et al.
(author)
-
- 2010
-
swepub:Mat__t
|
|
| 2. |
- Aad, G., et al.
(author)
-
- 2011
-
swepub:Mat__t
|
|
| 3. |
- Aad, G., et al.
(author)
-
- 2011
-
swepub:Mat__t (peer-reviewed)
|
|
| 4. |
|
|
| 5. |
- Aad, G., et al.
(author)
-
- 2010
-
swepub:Mat__t
|
|
| 6. |
- Aad, G., et al.
(author)
-
- 2010
-
swepub:Mat__t
|
|
| 7. |
- Aad, G., et al.
(author)
-
- 2011
-
swepub:Mat__t (peer-reviewed)
|
|
| 8. |
- Aad, G., et al.
(author)
-
- 2011
-
swepub:Mat__t (peer-reviewed)
|
|
| 9. |
- Aad, G., et al.
(author)
-
- 2011
-
swepub:Mat__t (peer-reviewed)
|
|
| 10. |
- Aad, G., et al.
(author)
-
- 2011
-
swepub:Mat__t (peer-reviewed)
|
|
| 11. |
- Aad, G., et al.
(author)
-
- 2011
-
swepub:Mat__t (peer-reviewed)
|
|
| 12. |
- Aad, G., et al.
(author)
-
- 2010
-
swepub:Mat__t
|
|
| 13. |
- Aad, G., et al.
(author)
-
- 2011
-
swepub:Mat__t (peer-reviewed)
|
|
| 14. |
- Aad, G., et al.
(author)
-
- 2011
-
swepub:Mat__t (peer-reviewed)
|
|
| 15. |
- Aad, G., et al.
(author)
-
- 2010
-
swepub:Mat__t (peer-reviewed)
|
|
| 16. |
- Aad, G., et al.
(author)
-
- 2011
-
swepub:Mat__t (peer-reviewed)
|
|
| 17. |
- Aad, G., et al.
(author)
-
- 2011
-
swepub:Mat__t (peer-reviewed)
|
|
| 18. |
|
|
| 19. |
|
|
| 20. |
- Benz, A. O., et al.
(author)
-
Hydrides in young stellar objects : Radiation tracers in a protostar-disk-outflow system
- 2010
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 521, s. L35-
-
Journal article (peer-reviewed)abstract
- Context. Hydrides of the most abundant heavier elements are fundamental molecules in cosmic chemistry. Some of them trace gas irradiated by UV or X-rays. Aims: We explore the abundances of major hydrides in W3 IRS5, a prototypical region of high-mass star formation. Methods: W3 IRS5 was observed by HIFI on the Herschel Space Observatory with deep integration (≃2500 s) in 8 spectral regions. Results: The target lines including CH, NH, H3O+, and the new molecules SH+, H2O+, and OH+ are detected. The H2O+ and OH+ J = 1-0 lines are found mostly in absorption, but also appear to exhibit weak emission (P-Cyg-like). Emission requires high density, thus originates most likely near the protostar. This is corroborated by the absence of line shifts relative to the young stellar object (YSO). In addition, H2O+ and OH+ also contain strong absorption components at a velocity shifted relative to W3 IRS5, which are attributed to foreground clouds. Conclusions: The molecular column densities derived from observations correlate well with the predictions of a model that assumes the main emission region is in outflow walls, heated and irradiated by protostellar UV radiation. Herschel is an ESA space observatory with science instruments provided by a European-led Principal Investigator consortia and with important participation from NASA.Appendix (page 5) is only available in electronic form at http://www.aanda.org
|
|
| 21. |
- Bruderer, S., et al.
(author)
-
Herschel/HIFI detections of hydrides towards AFGL 2591. Envelope emission versus tenuous cloud absorption
- 2010
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 521, s. L44-
-
Journal article (peer-reviewed)abstract
- The Heterodyne Instrument for the Far Infrared (HIFI) onboard the Herschel Space Observatory allows the first observations of light diatomic molecules at high spectral resolution and in multiple transitions. Here, we report deep integrations using HIFI in different lines of hydrides towards the high-mass star forming region AFGL 2591. Detected are CH, CH+, NH, OH+, H2O+, while NH+ and SH+ have not been detected. All molecules except for CH and CH+ are seen in absorption with low excitation temperatures and at velocities different from the systemic velocity of the protostellar envelope. Surprisingly, the CH(JF,P = 3/22,- - 1/21,+ ) and CH+(J = 1-0, J = 2-1) lines are detected in emission at the systemic velocity. We can assign the absorption features to a foreground cloud and an outflow lobe, while the CH and CH+ emission stems from the envelope. The observed abundance and excitation of CH and CH+ can be explained in the scenario of FUV irradiated outflow walls, where a cavity etched out by the outflow allows protostellar FUV photons to irradiate and heat the envelope at larger distances driving the chemical reactions that produce these molecules. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Apppendices and Table 1 (pages 6 to 7) are only available in electronic form at http://www.aanda.org
|
|
| 22. |
- Wampfler, S. F., et al.
(author)
-
Herschel observations of the hydroxyl radical (OH) in young stellar objects
- 2010
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 521, s. L36-
-
Journal article (peer-reviewed)abstract
- Aims: “Water In Star-forming regions with Herschel” (WISH) is a Herschel key program investigating the water chemistry in young stellar objects (YSOs) during protostellar evolution. Hydroxyl (OH) is one of the reactants in the chemical network most closely linked to the formation and destruction of H2O. High-temperature (T ⪆ 250 K) chemistry connects OH and H2O through the OH + H2 Leftrightarrow H2O + H reactions. Formation of H2O from OH is efficient in the high-temperature regime found in shocks and the innermost part of protostellar envelopes. Moreover, in the presence of UV photons, OH can be produced from the photo-dissociation of H2O through H2O + γUV Rightarrow OH + H. Methods: High-resolution spectroscopy of the 163.12 μm triplet of OH towards HH 46 and NGC 1333 IRAS 2A was carried out with the Heterodyne Instrument for the Far Infrared (HIFI) on board the Herschel Space Observatory. The low- and intermediate-mass protostars HH 46, TMR 1, IRAS 15398-3359, DK Cha, NGC 7129 FIRS 2, and NGC 1333 IRAS 2A were observed with the Photodetector Array Camera and Spectrometer (PACS) on Herschel in four transitions of OH and two [O i] lines. Results: The OH transitions at 79, 84, 119, and 163 μm and [O i] emission at 63 and 145 μm were detected with PACS towards the class I low-mass YSOs as well as the intermediate-mass and class I Herbig Ae sources. No OH emission was detected from the class 0 YSO NGC 1333 IRAS 2A, though the 119 μm was detected in absorption. With HIFI, the 163.12 μm was not detected from HH 46 and only tentatively detected from NGC 1333 IRAS 2A. The combination of the PACS and HIFI results for HH 46 constrains the line width (FWHM ⪆ 11 km s-1) and indicates that the OH emission likely originates from shocked gas. This scenario is supported by trends of the OH flux increasing with the [O i] flux and the bolometric luminosity, as found in our sample. Similar OH line ratios for most sources suggest that OH has comparable excitation temperatures despite the different physical properties of the sources. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendices (page 6) are only available in electronic form at http://www.aanda.org
|
|
| 23. |
|
|
