A SURVEY OF MOLECULAR HYDROGEN IN THE CRAB NEBULA

作者：Loh E D^*; Baldwin J A; Curtis Z K; Ferland G J; O'Dell C R; Fabian A C; Salome Philippe

来源：Astrophysical Journal, The - Supplement Series, 2011, 194(2): 30.

DOI：10.1088/0067-0049/194/2/30

• ISM: individual objects (Crab Nebula, M1)
• ISM: supernova remnants

We have carried out a near-infrared, narrowband imaging survey of the Crab Nebula, in the H-2 2.12 mu m and Br gamma 2.17 mu m lines, using the Spartan Infrared camera on the SOAR Telescope. Over a 2.'8 x 5.'1 area that encompasses about 2/3 of the full visible extent of the Crab, we detect 55 knots that emit strongly in the H-2 line. We catalog the observed properties of these knots. We show that they are in or next to the filaments that are seen in optical-passband emission lines. Comparison to Hubble Space Telescope [S II] and [0 m] images shows that the H-2 knots are strongly associated with compact regions of low-ionization gas. We also find evidence of many additional, fainter H-2 features, both discrete knots and long streamers following gas that emits strongly in [S A pixel-by-pixel analysis shows that about 6% of the Crab's projected surface area has significant H-2 emission that correlates with [S II] emission. We measured radial velocities of the [S II] lambda 6716 emission lines from 47 of the cataloged knots and find that most are on the far (receding) side of the nebula. We also detect Br gamma emission. It is right at the limit of our survey, and our Br gamma filter cuts off part of the expected velocity range. But clearly the Br gamma emission has a quite different morphology than the H-2 knots, following the long linear filaments that are seen in Ha and in [O III] optical emission lines.

• 出版日期2011-6