Probing habitable regions with SRG/eROSITA

Abstract

Stellar high-energy radiation is a key driver of atmospheric erosion and evolution in exoplanets, directly affecting their long-term habitability. We present a comprehensive study on stellar high-energy radiation and its impact on exoplanetary atmospheres, leveraging data from the \textit{SRG/eROSITA} all-sky survey. Our sample consists of 3750 main-sequence stars identified by cross-matching with \textit{Gaia} DR3. Utilizing X-ray spectral fits from the \textit{eROSITA} catalog, we computed X-ray ($L_X$) and combined extreme-ultraviolet (EUV) luminosities ($L_{\mathrm{EUV}}$), which we used to derive XUV fluxes at the habitable zone ($F_{\mathrm{XUV},\mathrm{HZ}}$). We find that the majority of stars in our sample are significantly more XUV-active than the Sun, with habitable zone fluxes ranging from $10^0$ to $10^5$ erg~cm${}^{-2}$~s${}^{-1}$. The ratio of $L_{\mathrm{XUV}}/L_{\mathrm{bol}}$ is found to be higher for cooler, magnetically active stars, highlighting their potentially hazardous nature for planetary atmospheres. Applying the energy-limited escape model, we computed atmospheric mass-loss rates for hypothetical earth-like planets located at the habitable zone of each star. We also present local maps for distances up to $500$~pc of the average XUV flux, revealing ``hazard zones'' where stellar radiation could significantly influence planetary atmospheric evolution. This work demonstrates the power of X-ray surveys in constraining the high-energy environments of exoplanets and underscores the critical role of stellar activity in planetary habitability.

8 pages, 11 figures

References in corpus (61)

• Gaia Data Release 3: Summary of the content and survey properties
• On the Absorption of X-rays in the Interstellar Medium
• Intrinsic Colors, Temperatures, and Bolometric Corrections of Pre-Main Sequence Stars
• The eROSITA X-ray telescope on SRG
• Evolution of the Solar Activity over Time and Effects on Planetary Atmospheres: I. High-energy Irradiances (1-1700 A)
• Atmospheric Escape from Hot Jupiters
• Understanding the Mass-Radius Relation for Sub-Neptunes: Radius as a Proxy for Composition
• Habitable Zones Around Main-Sequence Stars: Dependence on Planetary Mass
• A Revised Age for Upper Scorpius and The Star-Formation History Among the F-Type Members of the Scorpius-Centaurus OB Association
• A giant comet-like cloud of hydrogen escaping the warm Neptune-mass exoplanet GJ 436b
• Core-powered mass loss and the radius distribution of small exoplanets
• Roche lobe effects on the atmospheric loss of "Hot Jupiters"
• Estimation of the XUV radiation onto close planets and their evaporation
• How Thermal Evolution and Mass Loss Sculpt Populations of Super-Earths and Sub-Neptunes: Application to the Kepler-11 System and Beyond
• The SRG/eROSITA all-sky survey: First X-ray catalogues and data release of the western Galactic hemisphere
• Helium in the eroding atmosphere of an exoplanet
• Evaporation of the planet HD189733b observed in HI Lyman-alpha
• The eROSITA Final Equatorial Depth Survey (eFEDS): The X-ray catalog
• The Interior Structure, Composition, and Evolution of Giant Planets
• On the theory of disc photoevaporation
• Ground-based detection of an extended helium atmosphere in the Saturn-mass exoplanet WASP-69b
• The Ultraviolet Radiation Environment Around M dwarf Exoplanet Host Stars
• The active lives of stars: a complete description of rotation and XUV evolution of F, G, K, and M dwarfs
• Lyman-$\alpha$ Transit Spectroscopy and the Neutral Hydrogen Tail of the Hot Neptune GJ436b
• The Extreme Ultraviolet and X-Ray Sun in Time: High-Energy Evolutionary Tracks of a Solar-Like Star
• Spectrally resolved helium absorption from the extended atmosphere of a warm Neptune-mass exoplanet
• The coronal X-ray - age relation and its implications for the evaporation of exoplanets
• NEXXUS: A comprehensive ROSAT survey of coronal X-ray emission among nearby solar-like stars
• A New Window into Escaping Exoplanet Atmospheres: 10830 Å Line of Helium
• Atmospheres of low-mass planets: the "boil-off"
• Effect of episodic accretion on the structure and the lithium depletion of low-mass stars and planet-hosting stars
• Gaia Data Release 3: Astrophysical parameters inference system (Apsis) I -- methods and content overview
• Bayesian Analysis of Hot Jupiter Radius Anomalies: Evidence for Ohmic Dissipation?
• Is Proxima Centauri b habitable? -- A study of atmospheric loss
• Magnetically controlled mass loss from extrasolar planets in close orbits
• Heating efficiency in hydrogen-dominated upper atmospheres
• Overcoming the limitations of the energy-limited approximation for planet atmospheric escape
• Mass-loss rates for transiting exoplanets
• Transit observations of the Hot Jupiter HD 189733b at X-ray wavelengths
• The Interaction of Venus-like, M-dwarf Planets with the Stellar Wind of Their Host Star
• Irradiation-driven escape of primordial planetary atmospheres II. Evaporation efficiency of sub-Neptunes through hot Jupiters
• Impacts of stellar evolution and dynamics on the habitable zone: The role of rotation and magnetic activity
• Coupling thermal evolution of planets and hydrodynamic atmospheric escape in MESA
• First eROSITA study of nearby M dwarfs and the rotation-activity relation in combination with TESS
• Near-ultraviolet Transmission Spectroscopy of HD 209458b: Evidence of Ionized Iron Beyond the Planetary Roche Lobe
• Swift UVOT near-UV transit observations of WASP-121 b
• A critical assessment of the applicability of the energy-limited approximation for estimating exoplanetary mass-loss rates
• The stellar content of the ROSAT all-sky survey
• Exoplanet X-ray irradiation and evaporation rates with eROSITA
• Stellar X-ray activity across the Hertzsprung-Russell diagram. I. Catalogs
• One Year in the Life of Young Suns: Data Constrained Corona-Wind Model of kappa1 Ceti
• Connection between planetary He I $\lambda$10830 Å absorption and extreme-ultraviolet emission of planet-host stars
• The eROSITA Final Equatorial-Depth Survey (eFEDS). The stellar counterparts of eROSITA sources identified by machine learning and Bayesian algorithms
• The imprint of X-ray photoevaporation of planet-forming discs on the orbital distribution of giant planets
• Three-dimensional dust mapping in the Orion Complex, combining Gaia-TGAS, 2MASS, and WISE
• Complete X-ray census of Mdwarfs in the solar Neighborhood I. GJ 745 AB: Coronal-hole Stars in the 10 pc Sample
• Assessing the capability of a model-based stellar XUV estimation
• Stellar X-ray activity and habitability revealed by ROSAT sky survey
• The high-energy environment of the heavy sub-Earth GJ 367 b indicates likely complete evaporation of its atmosphere
• SRG/eROSITA 3D mapping of the ISM using X-ray absorption spectroscopy
• Is the high-energy environment of K2-18b special?