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ERRATUM: FERMI Large Area Telescope Study of Cosmic-Rays and the Interstellar Medium in Nearby Molecular CloudsIn the published version of the paper, errors were made in calculating the exposure time due to an analysis mistake. While they do not affect gas emissivities of the R CrA and Cepheus & Polaris flare regions significantly (the differences are within the systematic uncertainty), that of the Chamaeleon region is increased by approx.20%. Although we claimed a difference of ∼50% in gas emissivity among these molecular cloud regions in the original paper, it is decreased to ∼30% (comparable to the sum of the statistical and systematic uncertainties) in the revised analysis. Therefore, our conclusion of the original paper, that a small variation (approx. 20%) of the CR density in the solar neighborhood exists, is not supported by the data if we take these uncertainties into account. On the other hand, the obtained XCO and XAv values, and the masses of gas calculated from them are not changed significantly (the differences are within the statistical errors). Errors and corrections in the original paper are summarized below. 1. In the Abstract (lines 5-6) and Section 3 (lines 4-5 in the 3rd paragraph) in the original paper, the gamma -ray emissivity above 250 MeV for the Chamaeleon region should be (7.2 +/- 0.1stat +/- 1.0sys) × 10(exp −27) photons/s/sr/H-atom, not (5.9 +/-0.1stat +0.9−1.0sys) × 10(exp −27) photons/s/sr/H-atom. 2. In the Abstract (lines 8-10), "Whereas the energy dependences of the emissivities agree well with that predicted from direct CR observations at the Earth, the measured emissivities from 250 MeV to 10 GeV indicate a variation of the CR density by approx.20% in the neighborhood of the solar system, even if we consider the systematic uncertainties." should be changed to "The energy dependences of the emissivities agree well with that predicted from direct CR observations at the Earth. Although the measured emissivities from 250 MeV to 10 GeV differ by approx.30% among these molecular cloud regions, the difference is not significant if we take the systematic uncertainty into account." 3. Table 1 and Figure 13, which show gas emissivities and spectra for the Chamaeleon region in the original paper, should be changed to the Table 1 and Figure 1 as shown below. 4. Figure 16, which compares Hi gas emissivities among several regions in the original paper, should be changed to Figure 2 as shown below. 5. The text from the line 13 to the last one in the first paragraph of Section 4.1, "The spectral shapes for the three regions..., indicating a difference of the CR density between the Chamaeleon and the others as shown in Figure 16." should be changed to the paragraph that follows. "The shaded area of each spectrum indicates the systematic uncertainty as described in Section 3. We note that the systematic uncertainty of the LAT effective area (5% at 100 MeV and 20% at 10 GeV; Rando et al. 2009) does not affect the relative value of emissivities. The effect of unresolved point sources is small; we have verified that the obtained emissivities are almost unaffected by decreasing the threshold for point sources from TS = 100 to TS = 50. We also confirmed that the residual excess of photons around (l = 280deg to 288deg, b = −20deg to −12deg; see the bottom panel of Figure 8) in the Chamaeleon region does not affect the local Hi emissivity very much. Thus the total systematic uncertainty is reasonably expressed by the shaded area shown in Fig. 1.
Document ID
20160005796
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
Authors
Ackermann, M.
(Deutsches Elektronen-Synchrotron Zeuthen, Germany)
Ajello, M.
(Stanford Univ. Stanford, CA, United States)
Allafort, A.
(Stanford Univ. Stanford, CA, United States)
Baldini, L.
(Istituto Nazionale di Fisica Nucleare Pisa, Italy)
Ballet, J.
(Universite Paris Diderot Paris, France)
Barbiellini, G.
(Trieste Univ. Italy)
Bastieri, D.
(Padua Univ. Italy)
Bechtol, K.
(Stanford Univ. Stanford, CA, United States)
Bellazzini, R.
(Istituto Nazionale di Fisica Nucleare Pisa, Italy)
Berenji, B.
(Stanford Univ. Stanford, CA, United States)
Blandford, R. D.
(Stanford Univ. Stanford, CA, United States)
Bloom, E. D.
(Stanford Univ. Stanford, CA, United States)
Bonamente, E.
(Perugia Univ. Perugia, Italy)
Borgland, A.W.
(Stanford Univ. Stanford, CA, United States)
Bottacini, E.
(Stanford Univ. Stanford, CA, United States)
Brandt, T. J.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Bregeon, J.
(Istituto Nazionale di Fisica Nucleare Pisa, Italy)
Brigida, M.
(Istituto Nazionale di Fisica Nucleare Bari, Italy)
Bruel, P.
(Centre National de la Recherche Scientifique Palaiseau, France)
Buehler, R.
(Stanford Univ. Stanford, CA, United States)
Busetto, G.
(Padua Univ. Italy)
S.Buson
(Padua Univ. Italy)
Caliandro, G. A.
(Universidad Autonoma de Barcelona (Spain) Spain)
Cameron, R. A.
(Stanford Univ. Stanford, CA, United States)
Caraveo, P. A.
(Istituto di Astrofisica Spaziale e Fisica Cosmica (INAF-IASF) Milan, Italy)
Ferrara, E. C.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Harding, A. K.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Nemmen, R.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Thompson, D. J.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Troja, E.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
May 4, 2016
Publication Date
November 6, 2013
Publication Information
Publication: The Astrophysical Journal
Publisher: The American Astronomical Society
Volume: 778
Issue: 1
e-ISSN: 1538-4357
Subject Category
Astrophysics
Report/Patent Number
GSFC-E-DAA-TN15920
Distribution Limits
Public
Copyright
Other
Keywords
emissivities
Polaris flare
obtainedXCOandXAvvalues

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