X-ray survey of the North-America and Pelican star-forming complex (NGC7000/IC5070)

Abstract

We present the first extensive X-ray study of the North-America and Pelican star-forming region (NGC7000/IC5070), with the aim of finding and characterizing its young stellar population. X-ray data from Chandra (four pointings) and XMM-Newton (seven pointings) were reduced and source detection was performed on each image. We complement the X-ray data with optical and near-IR data from the IPHAS, UKIDSS, and 2MASS catalogs, and with other published optical and Spitzer IR data. More than 700 X-ray sources are detected, the majority of which have an optical/NIR counterpart. This allows to identify young stars in different stages of formation. Less than 30% of X-ray sources are identified with a previously known young star. We argue that most X-ray sources with an optical/NIR counterpart, except perhaps for a few tens at near-zero reddening, are likely candidate members of the star-forming region, on the basis of both their optical/NIR magnitudes and colors, and of X-ray properties like spectrum hardness or flux variations. They are characterized by a wide range of extinction, and sometimes near-IR excesses, both of which prevent derivation of accurate stellar parameters. The optical color-magnitude diagram suggests ages between 1-10~Myrs. The X-ray members have a very complex spatial distribution with some degree of subclustering, qualitatively similar to that of previously known members. The distribution of X-ray sources relative to IR-excess objects found with Spitzer is sometimes suggestive of sequential star formation, especially near the Gulf of Mexico region, probably triggered by the O5 star illuminating the whole region. Around this latter star no enhancement in the young star density is found, in agreement with previous results. We also determine the local optical/IR reddening law, and compute an updated reddening map of the entire region.

24 pages, 38 figures, 5 tables; accepted by A&A

References in corpus (14)

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• The UKIRT Wide Field Camera ZYJHK Photometric System: Calibration from 2MASS
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• Classical T Tauri stars with VPHAS$+$: I: H$\alpha$ and $u$-band accretion rates in the Lagoon Nebula M8
• Outflows, Dusty Cores, and a Burst of Star Formation in the North America and Pelican Nebulae
• High Resolution Optical and NIR Spectra of HBC 722
• X-ray emission from an FU Ori star in early outburst: HBC 722

Cited by in corpus (13)

• The Formation of a Stellar Association in the NGC 7000/IC 5070 Complex: Results from Kinematic Analysis of Stars and Gas
• The Villafranca catalog of Galactic OB groups: I. Systems with O2-O3.5 stars
• The First Extensive Spectroscopic Study of Young Stars in the North America and Pelican Nebulae Region
• A ZTF Look at Optical Variability of Young Stellar Objects in the North America and Pelican Nebulae Complex
• A wide-area photometric and astrometric (Gaia DR2) study of the young cluster NGC 6530
• A Comparison of the X-ray Properties of FU Ori-type Stars to Generic Young Stellar Objects
• The low-mass pre-main-sequence population of Sco OB1
• Searching for Molecular Outflows with Support Vector Machines: Dark Cloud Complex in Cygnus
• A Naive Bayes Classifier for identifying Class II YSOs
• Low mass star formation and subclustering in the HII regions RCW 32, 33 and 27 of the Vela Molecular Ridge. A photometric diagnostics to identify M-type stars
• Clustering of low mass stars around Herbig Be star IL Cep -- Evidence of "Rocket Effect" using Gaia EDR3 ?
• Long-term BVRI photometric light curves of 15 PMS stars in the IC 5070 star-forming region
• High-resolution CARMA Observation of Molecular Gas in the North America and Pelican Nebulae