Critical Accretion Disk

Publications of the Astronomical Society of Japan

Fukue, Jun¹ 

[1] Astronomical Institute, Osaka Kyoiku University, Asahigaoka, Kashiwara, Osaka 582-8582

关键词: "accretion;    accretion disks";    "black hole physics";    "galaxies: active";    microquasars;    "stars: winds;    outflows";    "X-rays: stars";   

DOI  :  10.1093/pasj/56.3.569

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

Forasupercriticalaccretionregime,weproposeacriticalaccretiondisk,wherethemass-accretionrateisregulatedjustatthecriticalratewiththehelpofwindmass-loss.Wefirstderiveacriticalradius,insideofwhichthestandardpictureisviolated,usingtheconditionthattheradiativeforceisbalancedbythegravityintheverticaldirection.Thecriticalradius$$r_mathrm{cr}$$isfoundtobe$$r_mathrm{cr}=(9sqrt{3}sigma_mathrm{T}/16picm_mathrm{p})dot{M}_mathrm{input}=1.95(dot{M}_mathrm{input}/dot{M}_mathrm{crit})r_mathrm{g}$$,where$$dot{M}_mathrm{input}$$isthemass-accretionrateattheouteredgeofthedisk,$$dot{M}_mathrm{crit}$$thecriticalaccretionrate,and$$r_mathrm{g}$$theSchwarzschildradiusofthecentralobject.Outsideofthiscriticalradius,thediskisinaradiation-pressuredominatedstandardstate,whileinsidethisradiusthediskisinacriticalstate,wheretheexcessmassisexpelledbywindandtheaccretionrateiskepttobejustatthecriticalrateatanyradiusinside$$r_mathrm{cr}$$.Insuchacriticalaccretiondisk,thediskthicknessis$$Hsim(1/6sqrt{3})r$$andthesurfacetemperatureis$$sigmaT^4sim(2/3sqrt{3})L_mathrm{E}/4pir^2$$,where$$L_mathrm{E}$$istheEddingtonluminosity.Thetotaldiskluminositybecomes$$L_mathrm{disk}sim(2/3sqrt{3})[ln(r_mathrm{cr}/r_mathrm{in})+1]L_mathrm{E}$$,where$$r_mathrm{in}$$istheinnerradius.Weapplythepresentmodeltomicroquasarsandnarrow-lineSeyfert1galaxies,whicharesupposedtobeundersupercriticalaccretion.

【 授权许可】

Unknown