What's Behind the Elephant's Trunk? Identifying Young Stellar Objects on the Outskirts of IC1396

Abstract

Empirically, the estimated lifetime of a typical protoplanetary disk is $<5-10$ Myr. However, the disk lifetimes required to produce a variety of observed exoplanetary systems may exceed this timescale. Some hypothesize that this inconsistency is due to estimating disk fractions at the cores of clusters, where radiation fields external to a star-disk system can photoevaporate the disk. To test this, we have observed a field on the western outskirts of the IC 1396 star-forming region with \textit{XMM-Newton} to identify new Class III YSO cluster members. Our X-ray sample is complete for YSOs down to $1.8M_{\odot }$. We use a subset of these X-ray sources that have near- and mid-infrared counterparts to determine the disk fraction for this field. We find that the fraction of X-ray-detected cluster members that host disks in the field we observe is $17_{-7}^{+10}\%$ (1$\sigma$), comparable with the $29_{-3}^{+4}\%$ found in an adjacent field centered on the cometary globule IC 1396A. We re-evaluate YSO identifications in the IC 1396A field using \textit{Gaia} parallaxes compared to previous color-cut-only identifications, finding that incorporating independent distance measurements provides key additional constraints. Given the existence of at least one massive star producing an external radiation field in the cluster core, the lack of statistically significant difference in disk fraction in each observed field suggests that disk lifetimes remain consistent as a function of distance from the cluster core.

arXiv comment19 pages, six figures. Published in Astronomical Journal

References in corpus (50)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• The NumPy array: a structure for efficient numerical computation
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Gaia mission
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• The Spitzer Space Telescope Mission
• Intrinsic Colors, Temperatures, and Bolometric Corrections of Pre-Main Sequence Stars
• Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2
• Disk Frequencies and Lifetimes in Young Clusters
• Protoplanetary Disks and Their Evolution
• The false positive rate of Kepler and the occurrence of planets
• Interpreting Spectral Energy Distributions from Young Stellar Objects. I. A grid of 200,000 YSO model SEDs
• astroquery: An Astronomical Web-Querying Package in Python
• The UKIRT Infrared Deep Sky Survey ZYJHK Photometric System: Passbands and Synthetic Colours
• The Relation Between Optical Extinction and Hydrogen Column Density in the Galaxy
• Estimating distances from parallaxes
• The WFCAM Science Archive
• The Star-formation History and Accretion-Disk Fraction Among the K-Type Members of the Scorpius-Centaurus OB Association
• The resolved fraction of the Cosmic X-ray Background
• Debris Disks: Structure, Composition, and Variability
• Evidence for Mass-dependent Circumstellar Disk Evolution in the 5 Myr-old Upper Scorpius OB Association
• The evolution of X-ray emission in young stars
• Protoplanetary disk lifetimes vs stellar mass and possible implications for giant planet populations
• Global X-ray properties of the Orion Nebula region
• High-Resolution Spectroscopy in Tr37: Gas Accretion Evolution in Evolved Dusty Disks
• X-ray Emission from T Tauri Stars and the Role of Accretion: Inferences from the XMM-Newton Extended Survey of the Taurus Molecular Cloud
• Searching the Entirety of Kepler Data. II. Occurrence Rate Estimates for FGK Stars
• X-ray Study of Triggered Star Formation and Protostars in IC 1396N
• A modular set of synthetic spectral energy distributions for young stellar objects
• A Spitzer View of the Young Open Cluster NGC 2264
• T Tauri candidates and accretion rates using IPHAS: method and application to IC1396
• Short dissipation times of proto-planetary discs - an artifact of selection effects?
• Viscous Evolution and Photoevaporation of Circumstellar Disks due to External FUV Radiation Fields
• Protostars in the Elephant Trunk Nebula
• Core-Halo Age Gradients and Star Formation in the Orion Nebula and NGC~2024 Young Stellar Clusters
• The Elephant Trunk Nebula and the Trumpler 37 cluster: Contribution of triggered star formation to the total population of an HII region
• An Improved Age-Activity Relationship for Cool Stars older than a Gigayear
• Confusion limited surveys: using WISE to quantify the rarity of warm dust around Kepler stars
• Mid-Infrared Variability of protostars in IC 1396A
• X-ray and IR Point Source Identification and Characteristics in the Embedded, Massive Star-Forming Region RCW 108
• X-ray view of IC348 in the light of an updated cluster census
• Disk Detective: Discovery of New Circumstellar Disk Candidates through Citizen Science
• The low-mass stellar population in the young cluster Tr37: Disk evolution, accretion, and environment
• Follow-up Imaging of Disk Candidates from the Disk Detective Citizen Science Project: New Discoveries and False-Positives in WISE Circumstellar Disk Surveys
• IRAS 20050+2720: Anatomy of a young stellar cluster
• Star Forming Regions in Cepheus
• IRAM and Gaia views of multi-episodic star formation in IC1396A: The origin and dynamics of the Class 0 protostar at the edge of an HII region
• Near-Infrared Variability of Low Mass Stars in IC 1396A and TR 37

Cited by in corpus (4)

• Membership analysis and 3D kinematics of the star-forming complex around Trumpler 37 using Gaia-DR3
• Star formation in IC1396: Kinematics and subcluster structure revealed by Gaia
• Search for Brown Dwarfs in IC 1396 with Subaru HSC: Interpreting the Impact of Environmental Factors on Sub-stellar Population
• Chandra Observations of Six Peter Pan Disks: Diversity of X-ray-driven Internal Photoevaporation Rates Doesn't Explain Their Rare Longevity