Sh 2-301: A Blistered H ii Region Undergoing Star Formation

Abstract

We present a multiwavelength study of the H ii region Sh 2-301 (S301) using deep optical data, near-infrared data, radio continuum data, and other archival data at longer wavelengths. A cluster of young stellar objects (YSOs) is identified in the northeast (NE) direction of S301. The Hα and radio continuum images trace the distribution of the ionized gas surrounding a massive star, ALS 207, and the S301 H ii region is bounded by an arc-like structure of gas and dust emission in the southeastern direction. The northwestern part of S301 seems to be devoid of gas and dust emission, while the presence of molecular material between the NE cluster and the central massive star ALS 207 is found. The distribution of warm dust emission, ionized gas, and neutral hydrogen together suggests a blistered morphology of the S301 H ii region powered by ALS 207, which appears to be located near the edge of the cloud. The location of the NE cluster embedded in the cold molecular cloud is found opposite to the blistered morphology. There is a noticeable age difference investigated between the massive star and the NE cluster. This age difference, pressure calculation, photodissociation regions, and the distribution of YSOs favor the positive feedback of the massive star ALS 207 in S301. On a wider scale of S301, the H ii region and the young stellar cluster are depicted toward the central region of a hub-filamentary system, which is evident in the infrared images.

Teutsch 76: a Deep Near-Infrared Study

“…The reported kinematical distance of the molecular cloud containing the T76 cluster and the Sh 2-141 H ii region is 7 ± 1.2 (Anderson et al, 2015;Pineault & Joncas, 2000). The distances to clusters with mean parallaxes smaller than ∼0.2 mas (distance ≥5 kpc) are better constrained by classical isochrone fitting methods (e.g., Pandey et al, 2022Pandey et al, , 2020aSharma et al, 2020Sharma et al, , 2017Sharma et al, , 2006Cantat-Gaudin et al, 2018;Phelps & Janes, 1994). Therefore, to further check the validity of PM distance estimation of T76 (∼5±1 kpc), we have used the PS1 g vs. (g − y) CMD for the stars in the cluster region along with the member stars as shown in Figure 4a.…”

Membership analysis and 3D kinematics of the star-forming complex around Trumpler 37 using Gaia-DR3

“…In addition to this, such studies aid in investigating the kinematics, dispersion, and evolution of the star-forming environment (Kuhn et al 2019; Karnath * swagat@das.uchile.cl / dasswagat77@gmail.com et al 2019; Pang et al 2020). Clusters with massive O and B type stars serve as important laboratories for star-formation since these massive stars ionize their surroundings, create H ii regions and shape the evolution of low mass star population in the vicinity through their feedback effects (Jose et al 2016;Samal et al 2014;Das et al 2017Das et al , 2021Zavagno et al 2020;Gupta et al 2021;Pandey et al 2022). Hence, the identification and characterization of cluster members are essential to investigate various star-formation properties, such as stars form hierarchically by the natural collapse of clumpy molecular clouds or by the collapsing gas formed through sweeping and compression of the cold neutral gas by the H ii regions and bubbles.…”

Membership Analysis and 3D Kinematics of the Star-forming Complex around Trumpler 37 Using Gaia-DR3

“…In addition to this, such studies aid in investigating the kinematics, dispersion, and evolution of the star-forming environment (Karnath et al 2019;Kuhn et al 2019;Pang et al 2020). Clusters with massive Oand B-type stars serve as important laboratories for star formation since these massive stars ionize their surroundings, create H II regions, and shape the evolution of the low-mass star population in the vicinity through their feedback effects (Samal et al 2014;Jose et al 2016;Das et al 2017Das et al , 2021Zavagno et al 2020;Gupta et al 2021;Pandey et al 2022). Hence, the identification and characterization of cluster members are essential to investigate various star formation properties, such as stars formed hierarchically by the natural collapse of clumpy molecular clouds or by the collapsing gas formed through sweeping and compression of the cold neutral gas by the H II regions and bubbles.…”