Revisiting the Local Interstellar Radiation Field using Gaia DR3
arXiv:2409.15778 · doi:10.1051/0004-6361/202451086
Abstract
Context: Dust grains in the interstellar medium are heated by the integrated radiation from stars in the Milky Way. A knowledge of the Local Interstellar Radiation Field (LISRF) is thus necessary to interpret observations of dust emission in the infrared and constrain (some of) the properties of interstellar grains. The LISRF representation most widely used in dust modelling still dates back to the seminal works of Mezger et al. (1982) and Mathis et al. (1983). Aims: A new version of the LISRF is presented, starting from the photometry of the Gaia Data Release 3 (DR3) and revisiting available data, among which observations from the Pioneer 10 and 11 probes. Methods: The LISRF contribution by direct starlight is estimated in the Gaia bands by summing fluxes of all stars in DR3; the LISRF is extrapolated from the optical to the ultraviolet and near-infrared, using the astrophysical parameters provided by DR3 for a subsample of Gaia stars; the correlation between dust emission at 100 um and residual diffuse emission in the Pioneer and other available maps is exploited to derive the contribution of dust-scattered starlight to the LISRF. Results: The new LISRF is significantly redder and emits ~30% more energy than the old model. The old LISRF is almost a factor two lower in the near-infrared, while in the optical it accounts only for direct starlight. For |b|<50 degree, diffuse starlight contributes on average to ~25% of the total radiation, 3x more than what predicted by literature estimates at high Galactic latitude. Conclusions: The new LISRF can modify the predicted mid-infrared dust emission beyond the uncertainties normally assumed between dust models and observational constraints; these differences should be taken into account to redefine the properties of small grains and of the carriers of the mid-infrared emission bands.
23 pages, 18 figures, accepted for publication in A&A
References in corpus (22)
- Array Programming with NumPy
- The Gaia mission
- Gaia Data Release 3: Summary of the content and survey properties
- Dust Masses, PAH Abundances, and Starlight Intensities in the SINGS Galaxy Sample
- The evolution of amorphous hydrocarbons in the ISM: dust modelling from a new vantage point
- Gaia Data Release 3: Astrophysical parameters inference system (Apsis) I -- methods and content overview
- Gaia Data Release 3: Analysis of the Gaia BP/RP spectra using the General Stellar Parameterizer from Photometry
- The Astrodust+PAH Model: A Unified Description of the Extinction, Emission, and Polarization from Dust in the Diffuse Interstellar Medium
- Old and young stellar populations in DustPedia galaxies and their role in dust heating
- The SPEAR Instrument and On-Orbit Performance
- GALEX Diffuse Observations of the Sky: The Data
- Mapping the Diffuse Ultraviolet Sky with GALEX
- Ultraviolet to optical diffuse sky emission as seen by the Hubble Space Telescope Faint Object Spectrograph
- THEMIS 2.0: A self-consistent model for dust extinction, emission, and polarisation
- A multi-band map of the natural night sky brightness including Gaia and Hipparcos integrated starlight
- The Gaia EDR3 view of Johnson-Kron-Cousins standard stars: the curated Landolt and Stetson collections
- Measurements of the mean diffuse galactic light spectrum in the 0.95 μm to 1.65 μm band from CIBER
- Gaia Data Release 3: The Gaia Andromeda Photometric Survey
- Dark dust II: Properties in the general field of the diffuse ISM
- Galactic Latitude Dependence of Near-Infrared Diffuse Galactic Light : Thermal Emission or Scattered Light?
- Using radioactivities to improve the search for nearby radio-quiet neutron stars
- Dust Scattered Radiation in the Galactic Poles