Investigation of the conspicuous infrared star cluster and star-forming region “RCW 38 IR Cluster”

Abstract

The infrared star cluster RCW 38 IR Cluster, which is also a massive star-forming region, is investigated. The results of observations with the SEST (Cerro La Silla, Chile) telescope on the 2.6-mm 12 CO spectral line and with SIMBA on the 1.2-mm continuum are given. The 12 CO observations revealed the existence of several molecular clouds, two of which (clouds 1 and 2) are connected with the object RCW 38 IR Cluster. Cloud 1 is a massive cloud, which has a depression in which the investigated object is embedded. It is not excluded that the depression was formed by the wind and/or emission from the young bright stars belonging to the star cluster. Rotation of cloud 2, around the axis having SE-NW direction, with an angular velocity -1 14 s 10 6 4 − ⋅ = ω. is also found. A red-shifted outflow with velocity ~+5.6 km/s, in the SE direction and perpendicular to the elongation of cloud 2 has also been found. The investigated cluster is associated with an IR point source IRAS 08573-4718, which has IR colors typical for a non-evolved embedded (in the cloud) stellar object. The cluster is also connected with a water maser. The SIMBA image shows the existence of a central bright condensation, coinciding with the cluster itself, and two extensions. One of these extensions (the one with SW-NE direction) coincides, both in place and shape, with cloud 2, so that the possibility that this extension might also be rotating like cloud 2 is not excluded . In the vicinity of these extensions there are condensations resembling HH objects.

The Two Molecular Clouds in RCW 38: Evidence for the Formation of the Youngest Super Star Cluster in the Milky Way Triggered by Cloud–cloud Collision

“…The finger cloud is not likely affected by self-absorption in 12 CO, since 12 CO and 13 CO show similar distributions in the declinationvelocity maps in Figures 3(c) and (f). We find three "bridging" 9 The two velocity features reported by Gyulbudaghian & May (2008) in 12 CO J = 1-0 correspond to the two peaks caused by self-absorption.…”

“…12 CO J = 1-0 observations with the SEST telescope at 45″ resolution for a small 160″×160″ region performed by Gyulbudaghian & May (2008) show two molecular clouds likely associated with RCW 38 in two different velocity ranges of −3 to +2 km s −1 and +3 to +8 km s −1 . In this paper, we present new molecular line observations toward RCW 38 obtained with NANTEN2, Mopra, and ASTE telescopes.…”

Large-scale mapping of the massive star-forming region RCW38 in the [CII] and PAH emission

“…Figure 2d shows the distribution of the 12 CO J=1-0 emission observed with NANTEN, where the velocity range is −3 to +12 km s −1 . For the central 2 ′ × 2 ′ area, Gyulbudaghian & May (2008) showed that the two clouds of 12 CO J=1-0 emission with the velocity ranges of −3-+2 km s −1 and +3-+8 km s −1 are associated with RCW 38 from the Swedish-ESO Submillimetre Telescope (SEST) observation. Therefore the CO cloud shown in Fig.…”

Star-forming region BBW 36 in puppis

“…In Table 2 In [16] it is supposed that these stars are early-type stars with dust discs, so that we can also suppose that the star N1 from Table 2 of this paper is an early-type star with dust envelope (or disc), and other stars from Tables 1 and 2 of this paper are late-type stars with dust discs (or envelopes).…”