Physical Conditions in Orion's Veil
Orion's veil consists of several layers of largely neutral gas lying between us and the main ionizing stars of the Orion Nebula. It is visible in 21 cm H I absorption and in optical and UV absorption lines of H I and other species. Toward theta super(1) Ori C, the veil has two remarkable proper...
Gespeichert in:
| Veröffentlicht in: | The Astrophysical journal 2004-07, Vol.609 (1), p.247-260 |
|---|---|
| Hauptverfasser: | , , , , , |
| Format: | Artikel |
| Sprache: | eng |
| Schlagworte: | |
| Online-Zugang: | Volltext bestellen |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| container_end_page | 260 |
|---|---|
| container_issue | 1 |
| container_start_page | 247 |
| container_title | The Astrophysical journal |
| container_volume | 609 |
| creator | Abel, N. P Brogan, C. L Ferland, G. J O’Dell, C. R Shaw, G Troland, T. H |
| description | Orion's veil consists of several layers of largely neutral gas lying between us and the main ionizing stars of the Orion Nebula. It is visible in 21 cm H I absorption and in optical and UV absorption lines of H I and other species. Toward theta super(1) Ori C, the veil has two remarkable properties, a high magnetic field (~100 mu G) and a surprising lack of H sub(2), given its total column density. Here we compute photoionization models of the veil to establish its gas density and its distance from theta super(1) Ori C. We use a greatly improved model of the H sub(2) molecule that determines level populations in 10 super(5) rotational/vibrational levels and provides improved estimates of H sub(2) destruction via the Lyman-Werner bands. Our best-fit photoionization models place the veil 1-3 pc in front of the star at a density of 10 super(3)-10 super(4) cm super(-3). Magnetic energy dominates the energy of nonthermal motions in at least one of the 21 cm H I velocity components. Therefore, the veil is the first interstellar environment in which magnetic dominance appears to exist. We find that the low ratio of H sub(2)/H super(0) ( |
| doi_str_mv | 10.1086/421009 |
| format | Article |
| fullrecord | <record><control><sourceid>proquest_O3W</sourceid><recordid>TN_cdi_iop_primary_10_1086_421009</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><sourcerecordid>17752694</sourcerecordid><originalsourceid>FETCH-LOGICAL-c375t-d55f49d9f5d922b8ea1ea5566e512244286807cf7d744d05625fa4ac5153d0ef3</originalsourceid><addsrcrecordid>eNplkFtLxDAQhYMoWFf9DRVRQagmaSZpHpfFGyysDyq-hZgLRrptTXYf9t_b0sUFfZoZ5uPMmYPQKcE3BFf8llGCsdxDGYGyKlgJYh9lGGNW8FK8H6KjlL6GkUqZofPnz00KRtf5rG1sWIW2SXlo8kXsu6uUv7lQH6MDr-vkTrZ1gl7v715mj8V88fA0m84LUwpYFRbAM2mlBysp_aicJk4DcO6AUMoYrXiFhfHCCsYsBk7Ba6YN9D4tdr6coMtRt4vt99qllVqGZFxd68a166SIEEC5ZDvQxDal6LzqYljquFEEqyEDNWbQgxdbRZ36H33UjQlpR4OUQjLcc9cjF9rudztkpIbIFMdSEUWZUJ0dbJ79h_8c_gGhi2-V</addsrcrecordid><sourcetype>Aggregation Database</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype><pqid>17752694</pqid></control><display><type>article</type><title>Physical Conditions in Orion's Veil</title><source>Institute of Physics Open Access Journal Titles</source><creator>Abel, N. P ; Brogan, C. L ; Ferland, G. J ; O’Dell, C. R ; Shaw, G ; Troland, T. H</creator><creatorcontrib>Abel, N. P ; Brogan, C. L ; Ferland, G. J ; O’Dell, C. R ; Shaw, G ; Troland, T. H</creatorcontrib><description>Orion's veil consists of several layers of largely neutral gas lying between us and the main ionizing stars of the Orion Nebula. It is visible in 21 cm H I absorption and in optical and UV absorption lines of H I and other species. Toward theta super(1) Ori C, the veil has two remarkable properties, a high magnetic field (~100 mu G) and a surprising lack of H sub(2), given its total column density. Here we compute photoionization models of the veil to establish its gas density and its distance from theta super(1) Ori C. We use a greatly improved model of the H sub(2) molecule that determines level populations in 10 super(5) rotational/vibrational levels and provides improved estimates of H sub(2) destruction via the Lyman-Werner bands. Our best-fit photoionization models place the veil 1-3 pc in front of the star at a density of 10 super(3)-10 super(4) cm super(-3). Magnetic energy dominates the energy of nonthermal motions in at least one of the 21 cm H I velocity components. Therefore, the veil is the first interstellar environment in which magnetic dominance appears to exist. We find that the low ratio of H sub(2)/H super(0) (<10 super(-4)) is a consequence of high UV flux incident on the veil due to its proximity to the Trapezium stars and the absence of small grains in the region.</description><identifier>ISSN: 0004-637X</identifier><identifier>EISSN: 1538-4357</identifier><identifier>DOI: 10.1086/421009</identifier><identifier>CODEN: ASJOAB</identifier><language>eng</language><publisher>Chicago, IL: IOP Publishing</publisher><subject>Astronomy ; Earth, ocean, space ; Exact sciences and technology ; H ii regions. Emission and reflection nebulae ; Interstellar medium (ism) and nebulae in milky way ; Stellar systems. Galactic and extragalactic objects and systems. The universe</subject><ispartof>The Astrophysical journal, 2004-07, Vol.609 (1), p.247-260</ispartof><rights>2004 INIST-CNRS</rights><lds50>peer_reviewed</lds50><oa>free_for_read</oa><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-c375t-d55f49d9f5d922b8ea1ea5566e512244286807cf7d744d05625fa4ac5153d0ef3</citedby><cites>FETCH-LOGICAL-c375t-d55f49d9f5d922b8ea1ea5566e512244286807cf7d744d05625fa4ac5153d0ef3</cites></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><linktopdf>$$Uhttps://iopscience.iop.org/article/10.1086/421009/pdf$$EPDF$$P50$$Giop$$H</linktopdf><link.rule.ids>314,780,784,27628,27924,27925,53931</link.rule.ids><linktorsrc>$$Uhttp://iopscience.iop.org/0004-637X/609/1/247$$EView_record_in_IOP_Publishing$$FView_record_in_$$GIOP_Publishing</linktorsrc><backlink>$$Uhttp://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetail&idt=15997940$$DView record in Pascal Francis$$Hfree_for_read</backlink></links><search><creatorcontrib>Abel, N. P</creatorcontrib><creatorcontrib>Brogan, C. L</creatorcontrib><creatorcontrib>Ferland, G. J</creatorcontrib><creatorcontrib>O’Dell, C. R</creatorcontrib><creatorcontrib>Shaw, G</creatorcontrib><creatorcontrib>Troland, T. H</creatorcontrib><title>Physical Conditions in Orion's Veil</title><title>The Astrophysical journal</title><description>Orion's veil consists of several layers of largely neutral gas lying between us and the main ionizing stars of the Orion Nebula. It is visible in 21 cm H I absorption and in optical and UV absorption lines of H I and other species. Toward theta super(1) Ori C, the veil has two remarkable properties, a high magnetic field (~100 mu G) and a surprising lack of H sub(2), given its total column density. Here we compute photoionization models of the veil to establish its gas density and its distance from theta super(1) Ori C. We use a greatly improved model of the H sub(2) molecule that determines level populations in 10 super(5) rotational/vibrational levels and provides improved estimates of H sub(2) destruction via the Lyman-Werner bands. Our best-fit photoionization models place the veil 1-3 pc in front of the star at a density of 10 super(3)-10 super(4) cm super(-3). Magnetic energy dominates the energy of nonthermal motions in at least one of the 21 cm H I velocity components. Therefore, the veil is the first interstellar environment in which magnetic dominance appears to exist. We find that the low ratio of H sub(2)/H super(0) (<10 super(-4)) is a consequence of high UV flux incident on the veil due to its proximity to the Trapezium stars and the absence of small grains in the region.</description><subject>Astronomy</subject><subject>Earth, ocean, space</subject><subject>Exact sciences and technology</subject><subject>H ii regions. Emission and reflection nebulae</subject><subject>Interstellar medium (ism) and nebulae in milky way</subject><subject>Stellar systems. Galactic and extragalactic objects and systems. The universe</subject><issn>0004-637X</issn><issn>1538-4357</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2004</creationdate><recordtype>article</recordtype><recordid>eNplkFtLxDAQhYMoWFf9DRVRQagmaSZpHpfFGyysDyq-hZgLRrptTXYf9t_b0sUFfZoZ5uPMmYPQKcE3BFf8llGCsdxDGYGyKlgJYh9lGGNW8FK8H6KjlL6GkUqZofPnz00KRtf5rG1sWIW2SXlo8kXsu6uUv7lQH6MDr-vkTrZ1gl7v715mj8V88fA0m84LUwpYFRbAM2mlBysp_aicJk4DcO6AUMoYrXiFhfHCCsYsBk7Ba6YN9D4tdr6coMtRt4vt99qllVqGZFxd68a166SIEEC5ZDvQxDal6LzqYljquFEEqyEDNWbQgxdbRZ36H33UjQlpR4OUQjLcc9cjF9rudztkpIbIFMdSEUWZUJ0dbJ79h_8c_gGhi2-V</recordid><startdate>20040701</startdate><enddate>20040701</enddate><creator>Abel, N. P</creator><creator>Brogan, C. L</creator><creator>Ferland, G. J</creator><creator>O’Dell, C. R</creator><creator>Shaw, G</creator><creator>Troland, T. H</creator><general>IOP Publishing</general><general>University of Chicago Press</general><scope>IQODW</scope><scope>AAYXX</scope><scope>CITATION</scope><scope>7TG</scope><scope>KL.</scope></search><sort><creationdate>20040701</creationdate><title>Physical Conditions in Orion's Veil</title><author>Abel, N. P ; Brogan, C. L ; Ferland, G. J ; O’Dell, C. R ; Shaw, G ; Troland, T. H</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c375t-d55f49d9f5d922b8ea1ea5566e512244286807cf7d744d05625fa4ac5153d0ef3</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2004</creationdate><topic>Astronomy</topic><topic>Earth, ocean, space</topic><topic>Exact sciences and technology</topic><topic>H ii regions. Emission and reflection nebulae</topic><topic>Interstellar medium (ism) and nebulae in milky way</topic><topic>Stellar systems. Galactic and extragalactic objects and systems. The universe</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Abel, N. P</creatorcontrib><creatorcontrib>Brogan, C. L</creatorcontrib><creatorcontrib>Ferland, G. J</creatorcontrib><creatorcontrib>O’Dell, C. R</creatorcontrib><creatorcontrib>Shaw, G</creatorcontrib><creatorcontrib>Troland, T. H</creatorcontrib><collection>Pascal-Francis</collection><collection>CrossRef</collection><collection>Meteorological & Geoastrophysical Abstracts</collection><collection>Meteorological & Geoastrophysical Abstracts - Academic</collection><jtitle>The Astrophysical journal</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext_linktorsrc</fulltext></delivery><addata><au>Abel, N. P</au><au>Brogan, C. L</au><au>Ferland, G. J</au><au>O’Dell, C. R</au><au>Shaw, G</au><au>Troland, T. H</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Physical Conditions in Orion's Veil</atitle><jtitle>The Astrophysical journal</jtitle><date>2004-07-01</date><risdate>2004</risdate><volume>609</volume><issue>1</issue><spage>247</spage><epage>260</epage><pages>247-260</pages><issn>0004-637X</issn><eissn>1538-4357</eissn><coden>ASJOAB</coden><abstract>Orion's veil consists of several layers of largely neutral gas lying between us and the main ionizing stars of the Orion Nebula. It is visible in 21 cm H I absorption and in optical and UV absorption lines of H I and other species. Toward theta super(1) Ori C, the veil has two remarkable properties, a high magnetic field (~100 mu G) and a surprising lack of H sub(2), given its total column density. Here we compute photoionization models of the veil to establish its gas density and its distance from theta super(1) Ori C. We use a greatly improved model of the H sub(2) molecule that determines level populations in 10 super(5) rotational/vibrational levels and provides improved estimates of H sub(2) destruction via the Lyman-Werner bands. Our best-fit photoionization models place the veil 1-3 pc in front of the star at a density of 10 super(3)-10 super(4) cm super(-3). Magnetic energy dominates the energy of nonthermal motions in at least one of the 21 cm H I velocity components. Therefore, the veil is the first interstellar environment in which magnetic dominance appears to exist. We find that the low ratio of H sub(2)/H super(0) (<10 super(-4)) is a consequence of high UV flux incident on the veil due to its proximity to the Trapezium stars and the absence of small grains in the region.</abstract><cop>Chicago, IL</cop><pub>IOP Publishing</pub><doi>10.1086/421009</doi><tpages>14</tpages><oa>free_for_read</oa></addata></record> |
| fulltext | fulltext_linktorsrc |
| identifier | ISSN: 0004-637X |
| ispartof | The Astrophysical journal, 2004-07, Vol.609 (1), p.247-260 |
| issn | 0004-637X 1538-4357 |
| language | eng |
| recordid | cdi_iop_primary_10_1086_421009 |
| source | Institute of Physics Open Access Journal Titles |
| subjects | Astronomy Earth, ocean, space Exact sciences and technology H ii regions. Emission and reflection nebulae Interstellar medium (ism) and nebulae in milky way Stellar systems. Galactic and extragalactic objects and systems. The universe |
| title | Physical Conditions in Orion's Veil |
| url | https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2024-12-28T23%3A45%3A10IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-proquest_O3W&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Physical%20Conditions%20in%20Orion's%20Veil&rft.jtitle=The%20Astrophysical%20journal&rft.au=Abel,%20N.%20P&rft.date=2004-07-01&rft.volume=609&rft.issue=1&rft.spage=247&rft.epage=260&rft.pages=247-260&rft.issn=0004-637X&rft.eissn=1538-4357&rft.coden=ASJOAB&rft_id=info:doi/10.1086/421009&rft_dat=%3Cproquest_O3W%3E17752694%3C/proquest_O3W%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_pqid=17752694&rft_id=info:pmid/&rfr_iscdi=true |