Spectral analysis of YSOs and other emission-line stars in the North America and Pelican nebulae region

TL;DR

This study analyzes the spectral properties of 34 stars in the North America and Pelican nebulae region, identifying emission-line stars and assessing their evolutionary status using multi-wavelength photometry.

Contribution

It provides the first spectral confirmation of emission lines in these stars and estimates their distances and evolutionary stages using combined spectral and photometric data.

Findings

19 stars show H alpha emission, some with additional emission lines.

Only 8 emission-line stars are within the NAP complex distance.

The region likely hosts a significant population of young, embedded stars.

Abstract

Far red spectra for 34 stars with V magnitudes between 15 and 18 in the direction of the North America and Pelican nebulae (NAP) star-forming region are obtained. Some of these stars were known earlier as emission-line objects, others were suspected as pre-main-sequence stars from photometry in the J, H, Ks and Vilnius systems. We confirm the presence of the H alpha line emission in the spectra of 19 stars, some of them exhibit also emission in the O I and Ca II lines. In some of the stars the H alpha absorption line is filled with emission. To estimate their evolutionary status, the spectral energy distributions, based on Vilnius, 2MASS, MSX and Spitzer photometry, are applied. Only eight emission-line stars are found to be located at a distance of the NAP complex. Others are either chromospherically active stars in front of the complex or distant luminous stars with H alpha absorption and emission components. For five stars with faint emission the data are not sufficient to estimate their distance. One star is found to be a heavily reddened K-supergiant located in the Outer arm. The stars, for which we failed to confirm the emission in H alpha, are mostly red dwarfs located in front of the NAP complex, two of them could be binaries with L-type components. Taking into account the stars suspected to be YSOs by their 2MASS colors we conclude that the NAP complex can possess a considerable population of young stars hidden behind the dust cloud.