The First Extensive Spectroscopic Study of Young Stars in the North America and Pelican Nebulae Region

Abstract

We present a spectroscopic survey of over 3400 potential members in the North America and Pelican nebulae (NAP) using several low-resolution ($R\approx$ 1300-2000) spectrographs: Palomar/Norris, WIYN/HYDRA, Keck/DEIMOS, and MMT/Hectospec. We identify 580 young stars as likely members of the NAP region based on criteria involving infrared excess, Li I 6708 absorption, X-ray emission, parallax, and proper motions. The spectral types of individual spectra are derived by fitting them with templates that are either empirical spectra of pre-main sequence stars, or model atmospheres. The templates are artificially veiled, and a best-fit combination of spectral type and veiling parameter is derived for each star. We use the spectral types with archival photometry to derive $V$-band extinction and stellar luminosity. From the H-R diagram, the median age of the young stars is about 1 Myr, with a luminosity dispersion of $\sim$0.3--0.4 dex. We investigate the photometric variability of the spectroscopic member sample using ZTF data, and conclude that photometric variability, while present, does not significantly contribute to the luminosity dispersion. While larger than the formal errors, the luminosity dispersion is smaller than if veiling were not taken into account in our spectral typing process. The measured ages of stellar kinematic groups, combined with inferred ages for embedded stellar populations revealed by Spitzer, suggests a sequential history of star formation in the NAP region.

54 pages, 26 figures, Accepted for publication in ApJ

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Cited by in corpus (15)

• SPICY: The Spitzer/IRAC Candidate YSO Catalog for the Inner Galactic Midplane
• An Improved HR Diagram for the Orion Trapezium Cluster
• A ZTF Look at Optical Variability of Young Stellar Objects in the North America and Pelican Nebulae Complex
• Application of a Steady-State Accretion Disk Model to Spectrophotometry and High-Resolution Spectra of Two Recent FU Ori Outbursts
• The old moving groups in the field of Taurus
• A Naive Bayes Classifier for identifying Class II YSOs
• Testing the star formation scaling relations in the clumps of the North American and Pelican cloud complexes
• Star formation in IC1396: Kinematics and subcluster structure revealed by Gaia
• Spectroscopic Confirmation of a Population of Isolated, Intermediate-Mass YSOs
• Optical and Near-Infrared Excesses are Correlated in T Tauri Stars
• A survey for variable young stars with small telescopes: IV -- Rotation Periods of YSOs in IC5070
• A survey for variable young stars with small telescopes: VII -- Spot Properties on YSOs in IC5070
• High-resolution CARMA Observation of Molecular Gas in the North America and Pelican Nebulae
• Survey of Hα emission-line stars in the star-forming region IC 5070
• Investigating star formation scenarios in the Milky Way using YSO distributions -- A pilot study