Abstract:
We present a multiwavelength study of the Galactic Hii region Sh2-297, located in the Canis Major OB1 complex.
Optical spectroscopic observations are used to constrain the spectral type of ionizing star HD 53623 as B0V.
The classical nature of this Hii region is affirmed by the low values of electron density and emission measure,
which are calculated to be 756 cm⁻³ and 9.15 × 10 ⁵ cm⁻ ⁶ pc using the radio continuum observations at 610 and
1280 MHz, and Very Large Array archival data at 1420 MHz. To understand local star formation, we identified
the young stellar object (YSO) candidates in a region of area ∼7.’ 5 × 7.’ 5 centered on Sh2-297 using grism slitless
spectroscopy (to identify the Hα emission line stars), and near infrared (NIR) observations. NIR YSO candidates are
further classified into various evolutionary stages using color–color and color–magnitude (CM) diagrams, giving
50 red sources (H −K >0.6) and 26 Class II-like sources. The mass and age range of the YSOs are estimated to
be ∼0.1–2M☉ and 0.5–2 Myr using optical (V/V−I) and NIR (J/J−H) CM diagrams. The mean age of the YSOs
is found to be ∼1 Myr, which is of the order of dynamical age of 1.07 Myr of the Hii region. Using the estimated
range of visual extinction (1.1–25 mag) from literature and NIR data for the region, spectral energy distribution
models have been implemented for selected YSOs which show masses and ages to be consistent with estimated
values. The spatial distribution of YSOs shows an evolutionary sequence, suggesting triggered star formation in the
region. The star formation seems to have propagated from the ionizing star toward the cold dark cloud LDN1657A
located west of Sh2-297.
