A Catalogue of Galactic Supernova Remnants: Documentation

2022 December version

D. A. Green
Cavendish Laboratory
19 J. J. Thomson Avenue
Cambridge CB3 0HE
UNITED KINGDOM

Contents of this document.
Other pages.

1. The Catalogue Format

This catalogue of Galactic supernova remnants (SNRs) is an updated version of those presented in detail in Green (1984, 1988) and in summary form in Green (1991, 1996, 2004, 2009, 2014, 2019) – hereafter Versions I, II, III, IV, V, VI, VII and VIII respectively – and on the Web, in versions of 1995 July, 1996 August, 1998 September, 2000 August, 2001 December, 2004 January, 2006 April, 2009 March and 2017 June. (Version IV, although published in 1996, was produced in 1993, and a detailed version of this was made available on the Web in 1993 November). The summary data from the 2001 December version of the catalogue was also published as an Appendix in Stephenson & Green (2002).

This, the 2022 December version of the catalogue contains 303 SNRs (which is nine more than in the previous version; fourteen remnants have been added, and five objects removed), with over three thousand references in the detailed listings, plus notes on many possible or probable remnants. For each remnant in the catalogue the following parameters are given.

In the detailed listings, for each remnant, notes on a variety of topics are given. First, it is noted if other Galactic coordinates have at times been used to label it (usually before good observations have revealed the full extent of the object), if the SNR is thought to be the remnant of a historical SN, or if the nature of the source as an SNR has been questioned (in which case an appropriate reference is usually given later in the entry). Brief descriptions of the remnant from the available radio, optical and X-ray observations as applicable are then given, together with notes on available distance determinations, and any point sources or pulsars in or near the object (although they may not necessarily be related to the remnant). Finally, appropriate published references to observations are given for each remnant, complete with journal, volume, page, and a short description of what information each paper contains (for radio observations these include the telescopes used, the observing frequencies and resolutions, together with any flux density determinations). These references are not complete, but cover representative and recent observations of the remnant – up to the end of 2021 in this version of the catalogue – and they should themselves include references to earlier work.

The references do not generally include large observational surveys – of particular interest in this respect are: the Effelsberg 100-m survey at 2.7 GHz of the Galactic plane 358° ≤ l ≤ 240°, |b| ≤ 5° by Reich et al. (1990) and Fürst et al. (1990a); reviews of the radio spectra of some SNRs by Kassim (1989), Kovalenko, Pynzar' & Udal'tsov (1994) and Trushkin (1998); the Parkes 64-m survey at 2.4 GHz of the Galactic plane 238° < l < 365°, |b| < 5° by Duncan et al. (1995) and Duncan et al. (1997); the Molonglo Galactic plane survey at 843 MHz of 245° < l < 355°, |b| < 1.°5 by Green et al. (1999); the survey of 345° < l < 255°, |b| < 5° at 8.35 and 14.35 GHz by Langston et al. (2000); Multi-Array Galactic Plane Imaging Survey (MAGPIS), see White, Becker & Helfand (2005) and Helfand et al. (2006); the VLA Galactic Plane Survey, see Stil et al. (2006); the GLOSTAR Galactic radio survey of the region 358° ≤ l ≤ 60°, |b| ≤ 1°, see Dokara et al. (2021); the survey of HI emission towards SNRs by Koo & Heiles (1991); surveys of IRAS observations of SNRs and their immediate surroundings by Arendt (1989) and by Saken, Fesen & Shull (1992); various Spitzer surveys of inner galaxy (Reach et al. 2006; Carey et al. 2009; Pinheiro Gonçalves et al. 2011); the catalogue by Fesen & Hurford (1996) of UV/optical/infra-red lines identified in SNRs; references to the first Fermi SNR catalogue (Acero et al. 2016) are included for the 30 `Classified Candidates' and 14 `Marginally Classified Candidates' remnants listed in Table 1, but not for the other remnants with non-detection; the H.E.S.S. high energy γ-ray Galactic plane survey (H.E.S.S. Collaboration: Abdalla et al. 2018a) and the 4th Fermi LAT Catalogue (Abdollahi et al. 2020). Also see Ferrand & Safi-Harb (2012), present a census of X-/γ-ray observations of Galactic SNRs and pulsar wind nebulae (PWNe), updates of which are available online.

The catalogue is available as a summary listing of the parameters for each remnant, and as detailed listings (with references) for each object. Also see the list of other names used for these SNRs, and the list of abbreviations for journals, proceedings and telescopes used in the detailed listings.

2. Revisions and Notes

2.1 Objects no longer thought to be SNRs

The following objects, which were listed in Version I of the catalogue were removed because they were no longer thought to be remnants, or were poorly observed (see Version II for references and further details): G2.4+1.4 (see also Gray 1994a; Goss & Lozinskaya 1995; Polcaro et al. 1995, Prajapati et al. 2019), G41.9−4.1 (=CTB 73, PKS 1920+06), G47.6+6.1 (=CTB 63), G53.9+0.3 (part of HC40), G93.4+1.8 (=NRAO 655), G123.2+2.9, G194.7+0.4 (the Origem Loop, but see below for more recent work), G287.8−0.5 (see below), G322.3−1.2 (=Kes 24) and G343.0−6.0 (but note that G343.0−6.0 was subsequently reinstated into the catalogue, due to improved observations, see below). Note that subsequently Leahy, Tian & Wang (2008) again proposed that a large (about 0.°5) radio shell, G53.9+0.2, as a possible old SNR. As noted above, this feature was included, as G53.9+0.3 (part of HC40), in Version I of the catalogue, but was subsequently removed, following the discussions of Caswell (1985) who concluded is was a thermal source (see also Velusamy, Goss & Arnal 1986; Zychová & Ehlerová 2016; Driessen et al. 2018). G358.4−1.9, which was listed in Version IV of the catalogue, was removed, as following the discussion of Gray (1994a), as it is not clear that this is a SNR. G240.9−0.9, G299.0+0.2 and G328.0+0.3, which were listed in 1995 July version of the catalogue, were removed from the 1996 August version, following the improved observations of Duncan et al. (1996) and Whiteoak & Green (1996). For the 1998 September revision of the catalogue G350.0−1.8 was incorporated into G350.0−2.0, and G337.0−0.1 refers to a smaller remnant than that previously catalogued with the same name. G112.0+1.2, G117.4+5.0, G152.2−1.2 and G211.7−1.1 – which were reported as SNRs by Bonsignori-Facondi & Tomasi (1979) – were removed from the 2001 December version of the catalogue, as the first three of these are not confirmed as SNRs from the Canadian Galactic Plane Survey (Roland Kothes, private communication). G10.0−0.3, which was regarded as a remnant – possibly associated with a soft-gamma repeater – was removed from the 2004 January version of the catalogue, as it is now thought to be radio nebula powered by a stellar wind (see Gaensler et al. 2001, Corbel & Eikenberry 2004, and references therein). G166.2+2.5 (=OA 184) was removed from the 2006 April version of the catalogue, as it was identified as an HII region by Foster et al. (2006). G84.9+0.5 was removed from Version VI of the catalogue, as it was identified as an HII region by Foster et al. (2007; see also Kothes et al. 2006). G16.8−1.1 was removed from Version VII of the catalogue (Sun et al. 2011; Stupar & Parker 2011). G192.8−1.1 was removed from the 2017 June version of the catalogue, as Gao et al. (2011) had shown this is not a SNR (Kang, Koo & Byun 2014). It was erroneously not removed in Version VII of the catalogue. Five entries (G20.4+0.1, G21.5−0.1, G23.6+0.3, G59.8+1.2 and G65.8−0.5) were removed from Version VIII of the catalogue, as Anderson et al. (2017), based on THOR and VGPS radio and IR survey observations, concluded they are not SNRs, but have been confused with HII regions. Anderson et al. also identified one other entry, G54.1+0.3 as not being a SNR. This used to be in the catalogue as a filled-centre remnant, as it shows a centrally brightened morphology in radio and X-ray observations, and contains a pulsar. It was reclassified as somewhat larger possible composite remnant when a larger, faint X-ray emission was identified, from which radio emission, with polarised loops was subsequently found. Thus G54.1+0.3 was retained in the catalogue as a composite remnant because of its X-ray and polarised radio emission, although it may be an isolated PWN.

In this version of the catalogue five entries have been removed. G11.1−1.0 and G16.4−0.5, which Gao et al. (2019) identified as HII regions rather than SNRs. (Gao et al. also identified G20.4+0.1 as an HII region, which had been removed from Version III of the catalogue.) G8.3−0.0, G10.5−0.0 and G14.3+0.1, which Dokara et al. (2021) identified as HII regions rather than SNRs. (Dokara et al. also identified G11.1−1.0 as an HII region.)

The following objects, which have been reported as SNRs, but have not been included in any of the versions of the SNR catalogue, have subsequently been shown not to be SNRs.

Also see further comments in Section 2.3, when there is evidence that some other objects which have been proposed SNRs are not remnants.

Some entries in the catalogue have been renamed, due to improved observations revealing a larger true extent for the object (previously G5.3−1.0 is now G5.4−1.2; G308.7+0.0 is now incorporated into G308.8−0.1). G337.0−0.1 now refers to a small (1.5 arcmin) remnant, rather than larger supposed remnant at this position (see Sarma et al. 1997), and G350.0−2.0 now incorporates the previously catalogued G350.0−1.8, based on the improved observations of Gaensler (1998). G106.6+2.9, which was proposed as a small remnant by Halpern et al. (2001), is incorporated into the larger catalogued remnant G106.3+2.7.

2.2 New SNRs

The following remnants were added to Version II of the catalogue: G0.9+0.1, G1.9+0.3, G5.9+3.1, G6.4+4.0, G8.7−0.1, G18.9−1.1, G20.0−0.2, G27.8+0.6, G30.7+1.0, G31.5−0.6, G36.6−0.7, G42.8+0.6, G45.7−0.4, G54.1+0.3, G73.9+0.9, G179.0+2.6, G312.4−0.4, G357.7+0.3 and G359.1−0.5.

The following remnants were added to Version III of the catalogue: G4.2−3.5, G5.2−2.6, G6.1+1.2, G8.7−5.0, G13.5+0.2, G15.1−1.6, G16.7+0.1, G17.4−2.3, G17.8−2.6, G30.7−2.0, G36.6+2.6, G43.9+1.6, G59.8+1.2, G65.1+0.6, G68.6−1.2, G69.7+1.0, G279.0+1.1, G284.3−1.8 (=MSH 10−53), G358.4−1.9 and G359.0−0.9 (although, as noted above, G59.8+1.2 and G358.4−1.9 have subsequently been removed).

The following remnants were added to Version IV of the catalogue: G59.5+0.1, G67.7+1.8, G84.9+0.5, G156.2+5.7, G318.9+0.4, G322.5−0.1, G343.1−2.3 and G348.5−0.0 (although, as noted above, G84.9+0.5 was subsequently removed).

The following remnants were added to 1995 July version of the catalogue: G1.0−0.1, G1.4−0.1, G3.7−0.2, G3.8+0.3, G28.8+1.5, G76.9+1.0, G272.2−3.2, G341.2+0.9, G354.1+0.1, G355.6−0.0, G356.3−0.3, G356.3−1.5 and G359.1+0.9.

The following remnants were added to the 1996 August version of the catalogue: G13.3−1.3, G286.5−1.2, G289.7−0.3, G294.1−0.0, G299.2−2.9, G299.6−0.5, G301.4−1.0, G308.1−0.7, G310.6−0.3, G310.8−0.4, G315.9−0.0, G317.3−0.2, G318.2+0.1, G320.6−1.6, G321.9−1.1, G327.4+1.0, G329.7+0.4, G342.1+0.9, G343.1−0.7, G345.7−0.2, G349.2−0.1, G351.7+0.8, G351.9−0.9 and G354.8−0.8.

The following remnants were added to the 1998 September version of the catalogue: G0.3+0.0, G32.1−0.9, G55.0+0.3, G63.7+1.1 and G182.4+4.3.

The following remnants were added to the 2000 August version of the catalogue: G7.0−0.1, G16.2−2.7, G29.6+0.1, G266.2−1.2 and G347.3−0.5.

The following remnants were added to the 2001 December version of the catalogue: G4.8+6.2, G28.6−0.1, G85.4+0.7, G85.9−0.6, G106.3+2.7, G292.2−0.5, G343.0−6.0, G353.9−2.0, G356.2+4.5 and G358.0+3.8.

G312.5−3.0 was added to Version V of the catalogue.

The following remnants were added to the 2006 April version of the catalogue: G5.5+0.3, G6.1+0.5, G6.5−0.4, G7.2+0.2, G8.3−0.0, G8.9+0.4, G9.7−0.0, G9.9−0.8, G10.5−0.0, G11.0−0.0, G11.1−0.7, G11.1−1.0, G11.1+0.1, G11.8−0.2, G12.2+0.3, G12.5+0.2, G12.7−0.0, G12.8−0.0, G14.1−0.1, G14.3+0.1, G15.4+0.1, G16.0−0.5, G16.4−0.5, G17.0−0.0, G17.4−0.1, G18.1−0.1, G18.6−0.2, G19.1+0.2, G20.4+0.1, G21.0−0.4, G21.5−0.1, G32.4+0.1, G96.0+2.0, G113.0+0.2 and G337.2+0.1 (as noted above, G8.3−0.0, G10.5−0.0, G11.1−1.0, G14.3+0.1, G16.4−0.5, G20.4+0.1 and G21.5−0.1 have subsequently been removed).

The following remnants were added to Version VI of the catalogue: G83.0−0.3, G108.2−0.6, G315.1+2.7, G332.5−5.6, G327.2−0.1, G350.1−0.3, G353.6−0.7, G355.4+0.7, G358.1+1.0 and G358.5−0.9. Note that G358.1+1.0 was in Versions VI and VII with the wrong name, G358.1+0.1, which has been corrected in this revision.

The following remnants were added to Version VII of the catalogue: G21.6−0.8, G25.1−2.3, G35.6−0.4, G38.7−1.3, G41.5+0.4, G42.0−0.1, G64.5+0.9, G65.8−0.5, G66.0−0.0, G67.6+0.9, G67.8+0.5, G152.4−2.1, G159.6+7.3, G178.2−4.2, G190.9−2.2, G213.0−0.6, G296.7−0.9, G306.3−0.9, G308.4−1.4, G310.6−1.6 and G322.1+0.0 (as noted above, G65.8−0.5 has subsequently been removed).

G70.0−21.5 and G351.0−5.4 were added to the 2017 June version of the catalogue.

The following remnants were added to Version VIII of the catalogue: G181.1+9.5, G323.7−1.0, G150.3+4.5 and G53.4+0.0.

The following remnants have been added to this version of the catalogue.

2.3 Possible and probable SNRs not listed in the catalogue

The following are possible or probable SNRs for which further observations are required to confirm their nature or parameters.

2.3.1 Radio

2.3.2 UV/Optical/Infra-red

2.3.3 X-ray/γ-ray

2.3.4 Other

It should also be noted: (a) Some large radio continuum, HI, CO or optical loops in the Galactic plane that may be parts of very large, old SNRs, but they have not been included in the See Berkhuijsen (1973), Grenier et al. (1989), Combi et al. (1995), Maciejewski et al. (1996), Kim & Koo (2000), Normandeau et al. (2000), Woermann, Gaylard & Otrupcek (2001), Stil & Irwin (2001), Uyanıker & Kothes (2002), Olano, Meschin & Niemela (2006), Borka (2007), Kang, Koo & Salter (2012), Xiao & Zhu (2014), Cichowolski et al. (2014), Sallmen et al. (2015), Bracco et al. (2020), Fesen et al. (2021) and Panopoulou et al. (2021). Gao & Han (2013) discuss the nature of the Origem Loop – a large radio loop – which has at times been regarded as a remnant. Also Koo, Kang & Salter (2006) and Kang & Koo (2007) identify faint Galactic HI features at forbidden velocities as indicators of old, otherwise undetectable SNRs. (b) Some large (> 10°) regions of X-ray emission that are indicative of a SNR are not included in the catalogue; e.g. the Monogem ring, near l=203°, b=+12° (see Nousek et al. 1981, Plucinsky et al. 1996, Thorsett et al. 2003, Amenomori et al. 2005, Plucinsky 2009, and references therein, plus Weinberger, Temporin & Stecklum 2006 and Reich, Reich & Sun 2020); in the Gum Nebula near l=250°, b=0° (see Leahy, Nousek & Garmire 1992, and also see Reynolds 1976, Dubner et al. 1992, Duncan et al. 1996, Reynoso & Dubner 1997, Heiles 1998, Pagani et al. 2012, Purcell et al. 2015, Knies, Sasaki & Plucinsky 2018); in Eridanus near l=200°, b=−40° (see Naranan et al. 1976, Burrows et al. 1993, Snowden et al. 1995, Heiles 1998, Boumis et al. 2001, Ryu et al. 2006); a large approximately 24° diameter, X-ray and optical loop in Antlia (see McCullough, Fields & Pavlidou 2002, Shinn et al. 2007). (c) The distinction between filled-centre remnants and pulsar wind nebulae (PWNe) is not clear, and isolated, generally faint, pulsar wind nebulae are also not included in the catalogue. See the catalogue of PWNe by Kaspi, Roberts & Harding (2006) (also see `Pulsar Wind Nebula Catalog' online), and the high-energy SNR and PWNe catalogue noted above.

2.4 Questionable SNRs listed in the catalogue

As noted in Versions II and IV of the catalogue, the following sources are listed as SNRs, although, as discussed in each case, the identifications are not certain: G5.4−1.2, G39.7−2.0 (=W50), G69.0+2.7 (=CTB 80), G318.9+0.4 and G357.7−0.1. The nature of G76.9+1.0 (an unusual radio source similar to G65.7+1.2), and of G354.1+0.1 (which may be similar to G357.7−0.1 (=MSH 17−39)) are also uncertain (see Landecker, Higgs & Wendker 1993 and Frail, Goss & Whiteoak 1994).

There are also some objects that have been identified as SNRs and are listed in the catalogue, although they have been barely resolved in the available observations, or are faint, and have not been well separated from confusing background or nearby thermal emission, and their identification as SNRs, or at least their parameters remain uncertain.

Acknowledgements

This research has made use of NASA's Astrophysics Data System Bibliographic Services, and the SIMBAD database, operated at CDS, Strasbourg, France.

References


Dave Green / Cambridge, UK /