Spatially resolved magnetic field structure in the disk of a T Tauri star

I. STEPHENS; L. LOONEY; W. KWON; MANUEL FERNANDEZ LOPEZ; A.M. HUGHES; L.G. MUNDY; R. CRUTCHER; Z.Y. LI; R. RAO

NATURE

NATURE PUBLISHING GROUP

Año: 2014

0028-0836

Magnetic fields in accretion disks play a dominant role during the star formation process but have hitherto been observationally poorly constrained. Field strengths have been inferred on T Tauri stars themselves and possibly in the innermost part of the accretion disk, but the strength and morphology of the field in the bulk of the disk have not been observed. Unresolved measurements of polarized emission (arising from elongated dust grains aligned perpendicular to the field) imply average fields aligned with the disks. Theoretically, the fields are expected to be largely toroidal, poloidal, or a mixture of the two, which imply different mechanisms for transporting angular momentum in the disks of actively accreting young stars such as HL Tau. Here we report resolved measurements of the polarized 1.25 mm continuum emission from HL Tau?s disk. The magnetic field on a scale of 80 AU is coincident with the major axis (210 AU diameter) of the disk. From this we conclude that the magnetic field inside the disk at this scale cannot be dominated by a vertical component, though a purely toroidal field does not fit the data well either. The unexpected morphology suggests that the magnetic field?s role for the accretion of a T Tauri star is more complex than the current theoretical understanding. <select> <option value="af">Afrikaans</option> <option value="sq">Albanian</option> <option value="ar">Arabic</option> <option value="hy">Armenian</option> <option value="az">Azerbaijani</option> <option value="eu">Basque</option> <option value="be">Belarusian</option> <option value="bg">Bulgarian</option> <option value="ca">Catalan</option> <option value="zh-CN">Chinese (Simplified)</option> <option value="zh-TW">Chinese (Traditional)</option> <option value="hr">Croatian</option> <option value="cs">Czech</option> <option value="da">Danish</option> <option selected="da" value="auto">Detect language</option> <option value="nl">Dutch</option> <option value="en">English</option> <option value="et">Estonian</option> <option value="tl">Filipino</option> <option value="fi">Finnish</option> <option value="fr">French</option> <option value="gl">Galician</option> <option value="ka">Georgian</option> <option value="de">German</option> <option value="el">Greek</option> <option value="ht">Haitian Creole</option> <option value="iw">Hebrew</option> <option value="hi">Hindi</option> <option value="hu">Hungarian</option> <option value="is">Icelandic</option> <option value="id">Indonesian</option> <option value="ga">Irish</option> <option value="it">Italian</option> <option value="ja">Japanese</option> <option value="ko">Korean</option> <option value="la">Latin</option> <option value="lv">Latvian</option> <option value="lt">Lithuanian</option> <option value="mk">Macedonian</option> <option value="ms">Malay</option> <option value="mt">Maltese</option> <option value="no">Norwegian</option> <option value="fa">Persian</option> <option value="pl">Polish</option> <option value="pt">Portuguese</option> <option value="ro">Romanian</option> <option value="ru">Russian</option> <option value="sr">Serbian</option> <option value="sk">Slovak</option> <option value="sl">Slovenian</option> <option value="es">Spanish</option> <option value="sw">Swahili</option> <option value="sv">Swedish</option> <option value="th">Thai</option> <option value="tr">Turkish</option> <option value="uk">Ukrainian</option> <option value="ur">Urdu</option> <option value="vi">Vietnamese</option> <option value="cy">Welsh</option> <option value="yi">Yiddish</option></select><span style="font-weight: bold; cursor: pointer; color: lightgrey;">⇄</span><select> <option value="af">Afrikaans</option> <option value="sq">Albanian</option> <option value="ar">Arabic</option> <option value="hy">Armenian</option> <option value="az">Azerbaijani</option> <option value="eu">Basque</option> <option value="be">Belarusian</option> <option value="bg">Bulgarian</option> <option value="ca">Catalan</option> <option value="zh-CN">Chinese (Simplified)</option> <option value="zh-TW">Chinese (Traditional)</option> <option value="hr">Croatian</option> <option value="cs">Czech</option> <option value="da">Danish</option> <option value="nl">Dutch</option> <option value="en">English</option> <option value="et">Estonian</option> <option value="tl">Filipino</option> <option value="fi">Finnish</option> <option value="fr">French</option> <option value="gl">Galician</option> <option value="ka">Georgian</option> <option value="de">German</option> <option value="el">Greek</option> <option value="ht">Haitian Creole</option> <option value="iw">Hebrew</option> <option value="hi">Hindi</option> <option value="hu">Hungarian</option> <option value="is">Icelandic</option> <option value="id">Indonesian</option> <option value="ga">Irish</option> <option value="it">Italian</option> <option value="ja">Japanese</option> <option value="ko">Korean</option> <option value="la">Latin</option> <option value="lv">Latvian</option> <option value="lt">Lithuanian</option> <option value="mk">Macedonian</option> <option value="ms">Malay</option> <option value="mt">Maltese</option> <option value="no">Norwegian</option> <option value="fa">Persian</option> <option value="pl">Polish</option> <option value="pt">Portuguese</option> <option value="ro">Romanian</option> <option value="ru">Russian</option> <option value="sr">Serbian</option> <option value="sk">Slovak</option> <option value="sl">Slovenian</option> <option selected="sl" value="es">Spanish</option> <option value="sw">Swahili</option> <option value="sv">Swedish</option> <option value="th">Thai</option> <option value="tr">Turkish</option> <option value="uk">Ukrainian</option> <option value="ur">Urdu</option> <option value="vi">Vietnamese</option> <option value="cy">Welsh</option> <option value="yi">Yiddish</option></select> <div style="text-align: left; background-color: rgb(235, 239, 249);">English (auto-detected) » Spanish</div> <div style="width: 444px; max-width: 444px; padding: 2px; min-height: 80px; border-width: 1px; border-style: solid; border-color: grey; background-color: rgb(255, 255, 255); text-align: justify;"><br /></div></div> </body> </html> <select> <option value="af">Afrikaans</option> <option value="sq">Albanian</option> <option value="ar">Arabic</option> <option value="hy">Armenian</option> <option value="az">Azerbaijani</option> <option value="eu">Basque</option> <option value="be">Belarusian</option> <option value="bg">Bulgarian</option> <option value="ca">Catalan</option> <option value="zh-CN">Chinese (Simplified)</option> <option value="zh-TW">Chinese (Traditional)</option> <option value="hr">Croatian</option> <option value="cs">Czech</option> <option value="da">Danish</option> <option selected="da" value="auto">Detect language</option> <option value="nl">Dutch</option> <option value="en">English</option> <option value="et">Estonian</option> <option value="tl">Filipino</option> <option value="fi">Finnish</option> <option value="fr">French</option> <option value="gl">Galician</option> <option value="ka">Georgian</option> <option value="de">German</option> <option value="el">Greek</option> <option value="ht">Haitian Creole</option> <option value="iw">Hebrew</option> <option value="hi">Hindi</option> <option value="hu">Hungarian</option> <option value="is">Icelandic</option> <option value="id">Indonesian</option> <option value="ga">Irish</option> <option value="it">Italian</option> <option value="ja">Japanese</option> <option value="ko">Korean</option> <option value="la">Latin</option> <option value="lv">Latvian</option> <option value="lt">Lithuanian</option> <option value="mk">Macedonian</option> <option value="ms">Malay</option> <option value="mt">Maltese</option> <option value="no">Norwegian</option> <option value="fa">Persian</option> <option value="pl">Polish</option> <option value="pt">Portuguese</option> <option value="ro">Romanian</option> <option value="ru">Russian</option> <option value="sr">Serbian</option> <option value="sk">Slovak</option> <option value="sl">Slovenian</option> <option value="es">Spanish</option> <option value="sw">Swahili</option> <option value="sv">Swedish</option> <option value="th">Thai</option> <option value="tr">Turkish</option> <option value="uk">Ukrainian</option> <option value="ur">Urdu</option> <option value="vi">Vietnamese</option> <option value="cy">Welsh</option> <option value="yi">Yiddish</option></select><span style="font-weight: bold; cursor: pointer; color: lightgrey;">⇄</span><select> <option value="af">Afrikaans</option> <option value="sq">Albanian</option> <option value="ar">Arabic</option> <option value="hy">Armenian</option> <option value="az">Azerbaijani</option> <option value="eu">Basque</option> <option value="be">Belarusian</option> <option value="bg">Bulgarian</option> <option value="ca">Catalan</option> <option value="zh-CN">Chinese (Simplified)</option> <option value="zh-TW">Chinese (Traditional)</option> <option value="hr">Croatian</option> <option value="cs">Czech</option> <option value="da">Danish</option> <option value="nl">Dutch</option> <option value="en">English</option> <option value="et">Estonian</option> <option value="tl">Filipino</option> <option value="fi">Finnish</option> <option value="fr">French</option> <option value="gl">Galician</option> <option value="ka">Georgian</option> <option value="de">German</option> <option value="el">Greek</option> <option value="ht">Haitian Creole</option> <option value="iw">Hebrew</option> <option value="hi">Hindi</option> <option value="hu">Hungarian</option> <option value="is">Icelandic</option> <option value="id">Indonesian</option> <option value="ga">Irish</option> <option value="it">Italian</option> <option value="ja">Japanese</option> <option value="ko">Korean</option> <option value="la">Latin</option> <option value="lv">Latvian</option> <option value="lt">Lithuanian</option> <option value="mk">Macedonian</option> <option value="ms">Malay</option> <option value="mt">Maltese</option> <option value="no">Norwegian</option> <option value="fa">Persian</option> <option value="pl">Polish</option> <option value="pt">Portuguese</option> <option value="ro">Romanian</option> <option value="ru">Russian</option> <option value="sr">Serbian</option> <option value="sk">Slovak</option> <option value="sl">Slovenian</option> <option selected="sl" value="es">Spanish</option> <option value="sw">Swahili</option> <option value="sv">Swedish</option> <option value="th">Thai</option> <option value="tr">Turkish</option> <option value="uk">Ukrainian</option> <option value="ur">Urdu</option> <option value="vi">Vietnamese</option> <option value="cy">Welsh</option> <option value="yi">Yiddish</option></select> <div style="text-align: left; background-color: rgb(235, 239, 249);">English (auto-detected) » Spanish</div> <div style="width: 444px; max-width: 444px; padding: 2px; min-height: 80px; border-width: 1px; border-style: solid; border-color: grey; background-color: rgb(255, 255, 255); text-align: justify;"><br /></div></div> </body> </html> <select> <option value="af">Afrikaans</option> <option value="sq">Albanian</option> <option value="ar">Arabic</option> <option value="hy">Armenian</option> <option value="az">Azerbaijani</option> <option value="eu">Basque</option> <option value="be">Belarusian</option> <option value="bg">Bulgarian</option> <option value="ca">Catalan</option> <option value="zh-CN">Chinese (Simplified)</option> <option value="zh-TW">Chinese (Traditional)</option> <option value="hr">Croatian</option> <option value="cs">Czech</option> <option value="da">Danish</option> <option selected="da" value="auto">Detect language</option> <option value="nl">Dutch</option> <option value="en">English</option> <option value="et">Estonian</option> <option value="tl">Filipino</option> <option value="fi">Finnish</option> <option value="fr">French</option> <option value="gl">Galician</option> <option value="ka">Georgian</option> <option value="de">German</option> <option value="el">Greek</option> <option value="ht">Haitian Creole</option> <option value="iw">Hebrew</option> <option value="hi">Hindi</option> <option value="hu">Hungarian</option> <option value="is">Icelandic</option> <option value="id">Indonesian</option> <option value="ga">Irish</option> <option value="it">Italian</option> <option value="ja">Japanese</option> <option value="ko">Korean</option> <option value="la">Latin</option> <option value="lv">Latvian</option> <option value="lt">Lithuanian</option> <option value="mk">Macedonian</option> <option value="ms">Malay</option> <option value="mt">Maltese</option> <option value="no">Norwegian</option> <option value="fa">Persian</option> <option value="pl">Polish</option> <option value="pt">Portuguese</option> <option value="ro">Romanian</option> <option value="ru">Russian</option> <option value="sr">Serbian</option> <option value="sk">Slovak</option> <option value="sl">Slovenian</option> <option value="es">Spanish</option> <option value="sw">Swahili</option> <option value="sv">Swedish</option> <option value="th">Thai</option> <option value="tr">Turkish</option> <option value="uk">Ukrainian</option> <option value="ur">Urdu</option> <option value="vi">Vietnamese</option> <option value="cy">Welsh</option> <option value="yi">Yiddish</option></select><span style="font-weight: bold; cursor: pointer; color: lightgrey;">⇄</span><select> <option value="af">Afrikaans</option> <option value="sq">Albanian</option> <option value="ar">Arabic</option> <option value="hy">Armenian</option> <option value="az">Azerbaijani</option> <option value="eu">Basque</option> <option value="be">Belarusian</option> <option value="bg">Bulgarian</option> <option value="ca">Catalan</option> <option value="zh-CN">Chinese (Simplified)</option> <option value="zh-TW">Chinese (Traditional)</option> <option value="hr">Croatian</option> <option value="cs">Czech</option> <option value="da">Danish</option> <option value="nl">Dutch</option> <option value="en">English</option> <option value="et">Estonian</option> <option value="tl">Filipino</option> <option value="fi">Finnish</option> <option value="fr">French</option> <option value="gl">Galician</option> <option value="ka">Georgian</option> <option value="de">German</option> <option value="el">Greek</option> <option value="ht">Haitian Creole</option> <option value="iw">Hebrew</option> <option value="hi">Hindi</option> <option value="hu">Hungarian</option> <option value="is">Icelandic</option> <option value="id">Indonesian</option> <option value="ga">Irish</option> <option value="it">Italian</option> <option value="ja">Japanese</option> <option value="ko">Korean</option> <option value="la">Latin</option> <option value="lv">Latvian</option> <option value="lt">Lithuanian</option> <option value="mk">Macedonian</option> <option value="ms">Malay</option> <option value="mt">Maltese</option> <option value="no">Norwegian</option> <option value="fa">Persian</option> <option value="pl">Polish</option> <option value="pt">Portuguese</option> <option value="ro">Romanian</option> <option value="ru">Russian</option> <option value="sr">Serbian</option> <option value="sk">Slovak</option> <option value="sl">Slovenian</option> <option selected="sl" value="es">Spanish</option> <option value="sw">Swahili</option> <option value="sv">Swedish</option> <option value="th">Thai</option> <option value="tr">Turkish</option> <option value="uk">Ukrainian</option> <option value="ur">Urdu</option> <option value="vi">Vietnamese</option> <option value="cy">Welsh</option> <option value="yi">Yiddish</option></select> <div style="text-align: left; background-color: rgb(235, 239, 249);">English (auto-detected) » Spanish</div> <div style="width: 444px; max-width: 444px; padding: 2px; min-height: 80px; border-width: 1px; border-style: solid; border-color: grey; background-color: rgb(255, 255, 255); text-align: justify;"><br /></div></div> </body> </html> Afrikaans Albanian Arabic Armenian Azerbaijani Basque Belarusian Bulgarian Catalan Chinese (Simplified) Chinese (Traditional) Croatian Czech Danish Detect language Dutch English Estonian Filipino Finnish French Galician Georgian German Greek Haitian Creole Hebrew Hindi Hungarian Icelandic Indonesian Irish Italian Japanese Korean Latin Latvian Lithuanian Macedonian Malay Maltese Norwegian Persian Polish Portuguese Romanian Russian Serbian Slovak Slovenian Spanish Swahili Swedish Thai Turkish Ukrainian Urdu Vietnamese Welsh Yiddish⇄ Afrikaans Albanian Arabic Armenian Azerbaijani Basque Belarusian Bulgarian Catalan Chinese (Simplified) Chinese (Traditional) Croatian Czech Danish Dutch English Estonian Filipino Finnish French Galician Georgian German Greek Haitian Creole Hebrew Hindi Hungarian Icelandic Indonesian Irish Italian Japanese Korean Latin Latvian Lithuanian Macedonian Malay Maltese Norwegian Persian Polish Portuguese Romanian Russian Serbian Slovak Slovenian Spanish Swahili Swedish Thai Turkish Ukrainian Urdu Vietnamese Welsh Yiddish English (auto-detected) » Spanish