25 research outputs found
Investigating star formation activity in the Sh 2-61 H II region
Using the multiwavelength data sets, we studied the star formation activity
in H II region Sh 2-61 (hereafter S61). We identified a clustering in the
region and estimated the membership using the Gaia proper motion data. The
physical environment of S61 is inspected using infrared to radio wavelength
images. We also determined the Lyman continuum flux associated with the H II
region and found that the H II region is formed by at least two massive stars
(S1 and S2). We also analyzed the 12CO (J =3-2) JCMT data of S61, and a shell
structure accompanying three molecular clumps are observed towards S61. We
found that the ionized gas in S61 is surrounded by dust and a molecular shell.
Many young stellar objects and three molecular clumps are observed at the
interface of the ionized gas and the surrounding gas. The pressure at the
interface is higher than in a typical cool molecular cloud.Comment: Paper is accepted for the publication in the Journal of Astrophysics
and Astronom
Merging Filaments and Hub Formation in the G083.09703.270 Molecular Complex
We uncover a hub-filament system associated with massive star formation in
the G083.09703.270. Diagnosed with simultaneous CO, CO, and
CO line observations, the region is found to host two distinct and
elongated filaments having separate velocity components, interacting spatially
and kinematically, that appear to have seeded the formation of a dense hub at
the intersection. A large velocity spread at the hub in addition to clear
bridging feature connecting the filaments in velocity are indicating merging of
filaments. Along the filaments axis, the velocity gradient reveals a global gas
motion with an increasing velocity dispersion inward to the hub signifying
turbulence. Altogether, the clustering of Class I sources, a high excitation
temperature, a high column density, and presence of a massive outflow at the
central hub suggest enhanced star formation. We propose that merging of
large-scale filaments and velocity gradients along filaments are the driving
factors in the mass accumulation process at the hub that have sequentially led
to the massive star formation. With two giant filaments merging to coincide
with a hub therein with ongoing star formation, this site serves as a benchmark
for the `filaments to clusters' star-forming paradigm.Comment: 12 pages, 7 figures, 1 table, accepted for publication in Ap
Structural Analysis of Open Cluster Bochum 2
We present the results from our deep optical photometric observations of
Bochum 2 (Boc2) star cluster obtained using the m Devasthal Fast Optical
Telescope along with archival photometric data from Pan-STARRS2/2MASS/UKIDSS
surveys. We also used high-quality parallax and proper motion data from the
Data Release 3. We found that the Boc2 cluster has a small size
(1.1 pc) and circular morphology. Using parallax of member stars
and isochrone fitting method, the distance of this cluster is estimated as
kpc. We have found that this cluster holds young ( Myr) and
massive (OO) stars as well as an older population of low mass stars. We
found that the massive stars have formed in the inner region of the Boc2
cluster in a recent epoch of star formation. We have derived mass function
slope () in the cluster region as in the mass range
M/M. The tidal radius of the Boc2 cluster ()
is much more than its observed radius ( pc). This suggests that most
of the low-mass stars in this cluster are the remains of an older population of
stars formed via an earlier epoch of star formation.Comment: accepted for publication in Journal of Astrophysics and Astronom
Dissecting the morphology of star forming complex S193
We have studied a star-forming complex S193 using near-infrared (NIR)
observations and other archival data covering optical to radio wavelengths. We
identified stellar clusters in the complex using the NIR photometric data and
estimated the membership and distance of the clusters. Using the mid-infrared
(MIR) and far-infrared (FIR) images, the distribution of the dust emission
around H\,{\sc ii} regions is traced in the complex. The column
density and temperature maps analysis reveal 16 cold dust clumps in the
complex. The H image and 1.4 GHz radio continuum emission map are
employed to study the ionised gas distribution and infer the spectral type and
the dynamical age of each H\,{\sc ii} region/ionised clump in the complex. The
CO(J =32) and CO(J =10) molecular line data hint at the
presence of two velocity components around [-43,-46] and [-47,-50] km/s, and
their spatial distribution reveals two overlapping zones toward the complex. By
investigating the immediate surroundings of the central cluster [BDS2003]57 and
the pressure calculations, we suggest that the feedback from the massive stars
seems responsible for the observed velocity gradient and might have triggered
the formation of the central cluster [BDS2003]57.}Comment: Accepted for publication in MNRAS, 20 pages, 15 figure