Structure & Magnetic Fields of the Star-Forming Region NGC 6334A T. H. Troland Physics & Astronomy Department University of Kentucky, USA OSU, June 21, 2006

Collaborators Elizabeth Mayo (University of Kentucky) Nick Abel (University of Kentucky) Anuj Sarma (DePaul University) Goren Sandell (NASA Ames / USRA)

Location of NGC 6334 in the Galaxy SHASSA l=351.0o, b=0.7o distance 1.7 kpc Southern H-Alpha Sky Survey Atlas (SHASSA)

Location of NGC 6334 in the Galaxy SHASSA l=351.0o, b=0.7o distance 1.7 kpc ? Cat’s Paw Nebula

Ionized gas - (H-alpha) 5 pc Optical H-alpha image from Antilhue Observatory, Chile, image by Daniel Verschatse http://www.astrosurf.com/antilhue/index.htm Antilhue Observatory

Ionized gas – 18cm radio continuum contours 5 pc Optical H-alpha image from Antilhue Observatory, Chile, image by Daniel Verschatse http://www.astrosurf.com/antilhue/index.htm Sarma et al. 2000

Molecular gas – C18O, J=2-1 5 pc H.E. Matthews, W. H. McCutcheon, G. J. White http://www.kent.ac.uk/physical-sciences/space/gw/n6334.html

Molecular gas – C18O, J=2-1 with 18 cm radio continuum contours 5 pc

2MASS

2MASS With C18O, J=2-1

2MASS With C18O, J=2-1 With 18cm radio continuum contours

2MASS

850  With 18cm radio continuum contours JMCT archival data

NGC 6334 A 850  dust continuum, contours at 0.9, 0.7, 0.5, 0.3, 0.1  Jy/beam With 18cm radio continuum contours 850  continuum, contours at 0.9, 0.7, 0.5, 0.3, 0.1 x 15 Jy/beam 1667 MHz continuum, contours at 0.9, 0.7, 0.5, 0.3, 0.1, 0.05, 0.025 x 0.98 Jy/beam 0.5 pc

Column densities and masses inferred from 850  Dust emission dust/N(H) = C computed by Cloudy (Ferland 1998) Also, dust  (Jy/beam)/Tdust So N(H)  (Jy/beam) / (C  Tdust) Results for peak of 15 Jy/beam (NGC 6334 A): N(H)peak  1  1024  (100/Td) cm-2 Av,peak  500  (100/Td) mag Used ISM grains, Si + graphite

SiO, J=7-6 v = 4.5 km/s With 850  contours Integrated SiO line with 850  contours at 0.9, 0.7, 0.5, 0.3, 0.1, 0.05, 0.025 x 15 Jy/beam v = 4.5 km/s JMCT archival data

18 cm radio continuum Northern lobe gap 1667 MHz continuum, contours at 0.9, 0.7, 0.5, 0.3, 0.1, 0.18, 0.15, 0.1, 0.05, 0.025  0.98 Jy/beam Central shell source (2  enlarged scale) Southern lobe Carral et al. (2002), 3.5 cm

3.3  PAH With 18cm radio continuum contours 3.3  PAH image with 1667 MHz continuum contours at 0.9, 0.7, 0.5, 0.3, 0.1, 0.18, 0.15, 0.1, 0.05, 0.025  0.98 Jy/beam Burton et al. 2000 (PAH)

Zeeman effect in 1665 and 1667 MHz OH absorption lines Quasi-thermally excited OH absorption lines observed against background H+ region. Zeeman effect reveals line-of-sight magnetic field, Blos.

Blos toward central shell source (G) /home63/aipsj/emayo/BCOMB/BFIELD.ps Note that beam for 1667 MHz is 8.3  5.1 arc sec, beam for 1665 MHz is 9.1  5.5 arc sec. Combined 1665 & 1667 Blos - Cell size 1”, beam  8.7”  5.3 This is the combined data, 1665 and 1667 MHz B values, averaged together with weights proportional to one over the errors squared.

Energetics of NGC 6334 A M  1000 Msolar (850 map) R  0.3 pc (850 map) v  4.5 km s-1 (SiO line width) Btot  1.2 mG (OH Zeeman data) Gravitational energy (2T)  2.4  1047 ergs Internal kinetic energy (W)  2.3  1047 ergs Magnetic energy (M)  1.2  1047 ergs

Some Conclusions for NGC 6334 A Northern lobe is not part of a bipolar H+ region, it is detached and separately excited. Magnetic fields are energetically important in the molecular cloud if OH absorption samples a representative volume.