Optical studies of supernova remnants: the nebula near $gamma$ Cygni

Journal Article · Sat Mar 01 04:00:00 EDT 1975 · Sov. Astron. AJ (Engl. Transl.), v. 19, no. 3, pp. 315-318

OSTI ID:4086265

Lozinskaya, T A

Detailed optical observations of the nebula near $gamma$ Cyg, identified with the supernova remnant corresponding to object No. 4 in Downes and Rinehart's list of Cyg X microwave sources, have been made with the 125-cm reflector of the Shternberg Astronomical Institute's Southern Station. Interference-filter photographs of the object in the H$alpha$, N II, S II, and O III lines have been taken. A series of interferometer observations of the nebula and the nearby H II region have been carried out in the H$alpha$ and lambda6584 N II lines with a high-contrast Fabry--Perot etalon and a contact electronic image converter. Spectrograms of the nebula at dispersions of 25, 60, and 240 A/mm in the 6000-- 7000 A range have been obtained with a grating spectrograph and an image converter. According to these observations, I/subH//sub alpha/approx. =10$sup - 3$ ergxcm$sup -2$xsec$sup -1$xsr$sup -1$ (corrected for interstellar absorption), I/subH//sub alpha//I/sub //subN//subI//subI//sub / =2.4, I/subH//sub alpha//I/sub //subS//subI//subI//sub /=7, I$sub 6731$/I$sub 6717$ =0.7 and V/sub LSR/=+9+-3 km/ sec. The mean halfwidths of the H$alpha$ and lambda6584 lines over the nebula are 49+-5 and 39+-5 km/sec, respectively. The expansion velocity of the nebula does not exceed 15 km/sec. It is shown that the nebula near $gamma$ Cyg cannot be a typical envelope formed in a supernova outburst such as the Cygnus Loop, IC 443, and W28. If the nebula is instead an H II zone, it would have the parameters T/sube/= (1-2) x10$sup 4$degreeK, N/sube/approx. =10$sup 2$ cm$sup - 3$, EMapprox. =10$sup 4$ cm$sup -6$xpc, Mapprox.30M/sub sun/, and u(/subS//subp// sub //sub approximately//sub 2//sub 5/pcxcm$sup -2$. The exciting star has not been found. The recombination radio emission of DR 4 arises from the nebula near $gamma$ Cyg, not from the diffuse background. (AIP)

• Research Organization: Shternberg Astronomical Institute, Moscow
• NSA Number: NSA-33-021004
• OSTI ID: 4086265
• Journal Information: Sov. Astron. AJ (Engl. Transl.), v. 19, no. 3, pp. 315-318, Journal Name: Sov. Astron. AJ (Engl. Transl.), v. 19, no. 3, pp. 315-318; ISSN SAAJA
• Country of Publication: United States
• Language: English

Related Subjects

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H2 REGIONS
N56200* --Physics (Astrophysics & Cosmology)--Stars
NEBULAE
NITROGEN
OXYGEN
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