Maps of Dust Infrared Emission for Use in Estimation of Reddening and Cosmic Microwave Background Radiation Foregrounds

By David Schlegel, Douglas P. Finkbeiner, M. Davis. 1998

We present a full-sky 100 μm map that is a reprocessed composite of the COBE/DIRBE and IRAS/ISSA maps, with the zodiacal foreground and confirmed point sources removed. Before using the ISSA maps, we remove the remaining artifacts from the IRAS scan pattern. Using the DIRBE 100 and 240 μm data, we have constructed a map of the dust temperature so that the 100 μm map may be converted to a map proportional to dust column density. The dust temperature varies from 17 to 21 K, which is modest but does modify the estimate of the dust column by a factor of 5. The result of these manipulations is a map with DIRBE quality calibration and IRAS resolution. A wealth of filamentary detail is apparent on many different scales at all Galactic latitudes. In high-latitude regions, the dust map correlates well with maps of H I emission, but deviations are coherent in the sky and are especially conspicuous in regions of saturation of H I emission toward denser clouds and of formation of H2 in molecular clouds. In contrast, high-velocity H I clouds are deficient in dust emission, as expected. To generate the full-sky dust maps, we must first remove zodiacal light contamination, as well as a possible cosmic infrared background (CIB). This is done via a regression analysis of the 100 μm DIRBE map against the Leiden-Dwingeloo map of H I emission, with corrections for the zodiacal light via a suitable expansion of the DIRBE 25 μm flux. This procedure removes virtually all traces of the zodiacal foreground. For the 100 μm map no significant CIB is detected. At longer wavelengths, where the zodiacal contamination is weaker, we detect the CIB at surprisingly high flux levels of 32 ± 13 nW m-2 sr-1 at 140 μm and of 17 ± 4 nW m-2 sr-1 at 240 μm (95% confidence). This integrated flux ~2 times that extrapolated from optical galaxies in the Hubble Deep Field. The primary use of these maps is likely to be as a new estimator of Galactic extinction. To calibrate our maps, we assume a standard reddening law and use the colors of elliptical galaxies to measure the reddening per unit flux density of 100 μm emission. We find consistent calibration using the B-R color distribution of a sample of the 106 brightest cluster ellipticals, as well as a sample of 384 ellipticals with B-V and Mg line strength measurements. For the latter sample, we use the correlation of intrinsic B-V versus Mg2 index to tighten the power of the test greatly. We demonstrate that the new maps are twice as accurate as the older Burstein-Heiles reddening estimates in regions of low and moderate reddening. The maps are expected to be significantly more accurate in regions of high reddening. These dust maps will also be useful for estimating millimeter emission that contaminates cosmic microwave background radiation experiments and for estimating soft X-ray absorption. We describe how to access our maps readily for general use.

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Citations in the corpus

STELLAR AND PLANETARY PROPERTIES OF K2 CAMPAIGN 1 CANDIDATES AND VALIDATION OF 17 PLANETS, INCLUDING A PLANET RECEIVING EARTH-LIKE INSOLATION (2015, methodology): “The NASA/IPAC Extragalactic Database, which reports the Schlafly & Finkbeiner (2011) recalibration of the Schlegel et al. (1998) extinction map as measured by COBE/ DIRBE and IRAS/ISSA, suggests that typical AV extinction values to the edge of the galaxy at this high Galactic latitude are ∼0.1 mag,…”
S-COSMOS: The Spitzer Legacy Survey of the Hubble Space Telescope ACS 2 deg2 COSMOS Field I: Survey Strategy and First Analysis (2007, methodology): “The black curve in Figure 6 is the power spectrum measured on the Schlegel et al. (1998) IRAS 100µm, scaled to 24µm using the square of the color ratio, S(100µm)/S(24µm), from Ingalls et al. (2004), as shown in equation 1.”
The nature of "dark" gamma-ray bursts (2010, methodology): “We then combined XRT and Galactic foreground extinction (Schlegel et al., 1998) corrected GROND data to establish a broad-band spectral energy distribution (SED) – see Fig.”
SPECTRAL CLASSIFICATION AND REDSHIFT MEASUREMENT FOR THE SDSS-III BARYON OSCILLATION SPECTROSCOPIC SURVEY (2012, methodology): “Colors and magnitudes for the galaxy selection cuts are corrected for Galactic extinction using Schlegel et al. (1998) dust maps.”
StarHorse : a Bayesian tool for determining stellar masses, ages, distances, and extinctions for field stars (2017, methodology): “When RJCE estimates were not available, we used E(B−V) estimates from (Schlegel et al. 1998) to estimate the prior AV .”
The Subaru/XMM-Newton Deep Survey (SXDS). IV. Evolution of Lyα Emitters from z = 3.1 to 5.7 in the 1 deg2 Field: Luminosity Functions and AGN (2007, methodology): “We correct the magnitudes of objects for Galactic extinction of E(B V ) ¼ 0:020 (Schlegel et al. 1998).”
A Large Stellar Evolution Database for Population Synthesis Studies. II. Stellar Models and Isochrones for an α-enhanced Metal Distribution (2006, methodology): “We have shifted the models to account for the well established reddening E(B − V ) =0.02 (Schlegel et al. 1998) and a distance modulus (m − M)J = 14.75, that corresponds to (m − M)0 = 14.72.”