Results 1 to 10 of about 4,968,402 (139)

Weak, extended water vapor emission in the Horsehead nebula [PDF]

Astronomy & Astrophysics
We analyzed archival Herschel observations of water vapor emission toward the Horsehead photon dominated region (PDR) along with supporting ground-based and airborne observations of CO isotopologs and fine structure lines of ionized and atomic carbon to ...
Lis Dariusz C., Maillard Vincent, Bron Emeric, Le Petit Franck, Goicoechea Javier R., Lu Ducheng, Teyssier David   +6 more
doaj   +2 more sources

PDRs4All

Astronomy & Astrophysics
Context. Conspicuous excess emission is present in the near-infrared (NIR) region in various objects, including reflection nebulae, planetary nebulae, and nearby galaxies. However, the spatial distribution and spectral shape of the excess emission remain
Onaka Takashi, Dartois Emmanuel, Peeters Els, Berné Olivier, Habart Emilie, Boersma Christiaan, Cami Jan, Fuente Asunción, Goicoechea Javier R., Lacinbala Ozan, Okada Yoko, Tielens Alexander G. G. M., Van De Putte Dries, Boulanger Francois, Pino Thomas, Zhang Yong   +15 more
doaj   +7 more sources

Photoionisation cross-sections of HCN, HNC, and HNO

Astronomy & Astrophysics
Aims. The primary aim of this work is to provide accurate photoionisation data for HCN, HNC, and HNO, including absolute total photoionisation cross sections and state-resolved partial cross sections.
Meng Ju, Wang Yitong, Wang Kedong
doaj   +1 more source

First detection of C2H+ in the interstellar medium★

Astronomy & Astrophysics
Despite the detection of nearly 350 molecules in the interstellar medium, almost half of which are carbon chains, the pathways that build molecular complexity remain poorly understood.
Jacob Arshia M., Menten Karl M., Brünken Sandra, Belloche Arnaud, Wyrowski Friedrich, Silva Weslley G. D. P., Asvany Oskar, Khan Sarwar, Kabanovic Slawa, Steenbakkers Kim, Groenenboom Gerrit C., Redlich Britta, Schlemmer Stephan   +12 more
doaj   +1 more source

Resolving dense photodissociation regions: The structure of photochemical fronts in three-dimensional gas distributions

Astronomy & Astrophysics
Context. For decades, the Orion Bar has been the prototypical photodissociation region (PDR). Viewed nearly edge-on, it offers a unique window into the stratified chemical structure of the atomic-to-molecular transition of the interstellar medium.
Gaches Brandt A. L., Bisbas Thomas G., Brendel Lothar, Zhu Zhengping   +3 more
doaj   +1 more source

Spatial distribution of organics in the Horsehead nebula: Signposts of chemistry driven by atomic carbon

Astronomy & Astrophysics
Complex organic molecules (COMs) are considered essential precursors to prebiotic species in the interstellar and circumstellar medium. Despite their astrobiological relevance, many aspects of the formation of COMs remain unclear, particularly the role ...
Hernández-Vera Claudio, Guzmán Viviana V., Pety Jérôme, Wong Ka Tat, Goicoechea Javier R., Le Petit Franck, Gerin Maryvonne, den Braber Aquiles, Carpenter John M., Maillard Vincent, Bron Emeric, Gratier Pierre, Roueff Evelyne   +12 more
doaj   +1 more source

Photoevaporation can reproduce extended H2 emission from protoplanetary disks imaged by JWST/MIRI-MRS

Astronomy & Astrophysics
Context. Understanding the dispersal of protoplanetary disks remains a central challenge in planet formation theory. Disk winds driven by magnetohydrodynamics (MHD) and/or photoevaporation are now recognized as primary agents of dispersal.
Nakatani R., Rosotti G., Tabone B., Sellek A.   +3 more
doaj   +1 more source

The impact of attenuation on cosmic-ray chemistry

Astronomy & Astrophysics
The chemistry of shielded molecular gas is primarily driven by energetic, charged particles dubbed cosmic rays (CRs), in particular those with energy levels under 1 GeV. CRs ionize molecular hydrogen and helium, the latter of which contributes greatly to
Roy Arghyadeb, Gaches Brandt A. L., Tan Jonathan C.   +2 more
doaj   +1 more source

High-resolution laboratory study of the ν2/ν4 bending motion of CH3+ and assignment of its astronomically observed lines

Astronomy & Astrophysics
Context. The methyl cation (CH3+) was discovered through the detection of a 7 μm (1400 cm−1) band observed in the d203-506 protoplanetary disk in the Orion nebula using the MIRI-MRS spectrometer on board the JWST.
Salomon Thomas, Schroetter Ilane, Berné Olivier, Changala P. Bryan, Martin-Drumel Marie-Aline, Okada Yoko, Röllig Markus, Schlemmer Stephan, Asvany Oskar   +8 more
doaj   +1 more source

JWST observations of photodissociation regions

Astronomy & Astrophysics
Context. The northwest photodissociation region (PDR) of the NGC 7023 reflection nebula has been observed with JWST spectroscopy, revealing the carbonaceous emission bands at a high level of detail.
Van De Putte D., Gordon K. D., Misselt K., Witt A. N., Abergel A., Noriega-Crespo A., Guillard P., Zannese M., Elyajouri M., Trahin B., Dell’ova P., Baes M., Klaassen P.   +12 more
doaj   +1 more source