A sharper view of the outer Galaxy at 1420 and 408 MHz from the Canadian Galactic Plane Survey – I. Revisiting the KR catalogue and new Gigahertz Peaked Spectrum sources

Abstract

Arcminute-resolution radio continuum images at 408 and 1420 MHz from the Canadian Galactic Plane Survey (CGPS) have been used to re-examine radio sources listed in the Kallas & Reich catalogue. This catalogue is of particular interest to Galactic studies as it lists both extended and compact radio sources found in the second Galactic quadrant. We have determined the nature (extended versus compact, Galactic versus extragalactic) of all of these bright radio sources. A number of large H II regions with no optical counterparts are highlighted along with a sample of large radio galaxies. Many sources previously thought to be extended Galactic objects are shown to be point sources. A sample of point sources with flat or rising spectra between 408 and 1420 MHz has been compiled, and within this sample likely Gigahertz Peaked Spectrum sources have been identified.

Submillimeter and Molecular Views of Three Galactic Ring-Like H Ii Regions

“…KR 7 (Sh 2-124) is a 12 ′ diameter H II region with a 1420 MHz flux density F 1420 = 2690 ± 81 mJy (Kerton 2006). Using a spherical, constant density model, a lower limit on the total emission rate of ionizing photons (N L ) can be derived from the observed radio flux density…”

Observational studies of the structure, content and environment of intermediate and high-mass star-forming regions

“…In Kerton (2006) KR 81 is listed an 6 diameter 1420 MHz radio continuum source. The white contours correspond to MSX brightness levels of 1.5 × 10 −6 , 3 × 10 −6 and 6 × 10 −6 W m −2 sr −1 from Figure 4.2.…”

“…The mass of the sub-mm source is 21 ± 8 M . If the dust temperature was instead assumed to be T d = 10 K, the column density would in- In Kerton (2006) KR 120 is listed an 6 diameter 1420 MHz radio continuum source.…”

A study of four galactic small H II regions: searching for spontaneous and sequential star formation scenarios

“…(Foster and Routledge, 2003). Based on CGPS 1420 MHz observation, flux density is F 1420 = 2690 ± 81 mJy (Kerton, 2006) and angular diameter is ∼ 6 pc ( Figure 2.2). To identify the exciting star of each H II region, the ionizing photon luminosity (N L ) can be derived from the observed radio flux density; the derived N L value can then be compared with the spectral type-temperature calibration for Galactic O and early B stars from Crowther (2005) (see Table 2.2).…”

“…For KR 7, the ionizing photon flux, log N L = 48.2 which corresponds to an exciting star of O9V star (Crowther, 2005) (Kerton, 2006). The estimated flux of ionizing photons from the exciting star, log N L = 47.2 corresponds to a single B0V star (Table 2.2).…”