J/A+A/565/A103 Anomalous microwave emission in Galactic clouds (Planck+, 2014)
Planck intermediate results.
XV. A study of anomalous microwave emission in Galactic clouds.
Planck Collaboration, Ade P.A.R., Aghanim N., Alves M.I.R., Arnaud M.,
Atrio-Barandela F., Aumont J., Baccigalupi C., Banday A.J., Barreiro R.B.,
Battaner E., Benabed K., Benoit-Levy A., Bernard J.-P., Bersanelli M.,
Bielewicz P., Bobin J., Bonaldi A., Bond J.R., Borrill J., Bouchet F.R.,
Boulanger F., Burigana C., Cardoso J.-F., Casassus S., Catalano A.,
Chamballu A., Chen X., Chiang H.C., Chiang L.-Y., Christensen P.R.,
Clements D.L., Colombi S., Colombo L.P.L., Couchot F., Crill B.P.,
Cuttaia F., Danese L., Davies R.D., Davis R.J., De Bernardis P.,
De Rosa A., De Zotti G., Delabrouille J., Desert F.-X., Dickinson C.,
Diego J.M., Donzelli S., Dore O., Dupac X., Ensslin T.A., Eriksen H.K.,
Finelli F., Forni O., Franceschi E., Galeotta S., Ganga K.,
Genova-Santos R.T., Ghosh T., Giard M., Gonzalez-Nuevo J., Gorski K.M.,
Gregorio A., Gruppuso A., Hansen F.K., Harrison D.L., Helou G.,
Hernandez-Monteagudo C., Hildebrandt S.R., Hivon E., Hobson M.,
Hornstrup A., Jaffe A.H., Jaffe T.R., Jones W.C., Keihaenen E.,
Keskitalo R., Kneissl R., Knoche J., Kunz M., Kurki-Suonio H.,
Laehteenmaeki A., Lamarre J.-M., Lasenby A., Lawrence C.R., Leonardi R.,
Liguori M., Lilje P.B., Linden-Vornle M., Lopez-Caniego M.,
Macias-Perez J.F., Maffei B., Maino D., Mandolesi N., Marshall D.J.,
Martin P.G., Martinez-Gonzalez E., Masi S., Massardi M., Matarrese S.,
Mazzotta P., Meinhold P.R., Melchiorri A., Mendes L., Mennella A.,
Migliaccio M., Miville-Deschenes M.-A., Moneti A., Montier L., Morgante G.,
Mortlock D., Munshi D., Naselsky P., Nati F., Natoli P.,
Norgaard-Nielsen H.U., Noviello F., Novikov D., Novikov I., Oxborrow C.A.,
Pagano L., Pajot F., Paladini R., Paoletti D., Patanchon G., Pearson T.J.,
Peel M., Perdereau O., Perrotta F., Piacentini F., Piat M., Pierpaoli E.,
Pietrobon D., Plaszczynski S., Pointecouteau E., Polenta G., Ponthieu N.,
Popa L., Pratt G.W., Prunet S., Puget J.-L., Rachen J.P., Rebolo R.,
Reich W., Reinecke M., Remazeilles M., Renault C., Ricciardi S., Riller T.,
Ristorcelli I., Rocha G., Rosset C., Roudier G., Rubino-Martin J.A.,
Rusholme B., Sandri M., Savini G., Scott D., Spencer L.D., Stolyarov V.,
Sutton D., Suur-Uski A.-S., Sygnet J.-F., Tauber J.A., Tavagnacco D.,
Terenzi L., Tibbs C.T., Toffolatti L., Tomasi M., Tristram M., Tucci M.,
Valenziano L., Valiviita J., Van Tent B., Varis J., Verstraete L.,
Vielva P., Villa F., Wandelt B.D., Watson R., Wilkinson A., Ysard N.,
Yvon D., Zacchei A., Zonca A.
<Astron. Astrophys., 565, A103-103 (2014)>
=2014A&A...565A.103P 2014A&A...565A.103P (SIMBAD/NED BibCode)
ADC_Keywords: H II regions ; Radio continuum
Keywords: HII regions - radiation mechanisms: general - radio continuum: ISM -
submillimeter: ISM
Abstract:
Anomalous microwave emission (AME) is believed to be due to electric
dipole radiation from small spinning dust grains. The aim of this
paper is a statistical study of the basic properties of AME regions
and the environment in which they emit. We used WMAP and Planck maps,
combined with ancillary radio and IR data, to construct a sample of 98
candidate AME sources, assembling SEDs for each source using aperture
photometry on 1°-smoothed maps from 0.408GHz up to 3000GHz.
Each spectrum is fitted with a simple model of free-free, synchrotron
(where necessary), cosmic microwave background (CMB), thermal dust,
and spinning dust components. We find that 42 of the 98 sources have
significant (>5σ) excess emission at frequencies between 20 and
60GHz. An analysis of the potential contribution of optically thick
free-free emission from ultra-compact HII regions, using IR colour
criteria, reduces the significant AME sample to 27 regions. The
spectrum of the AME is consistent with model spectra of spinning dust.
Peak frequencies are in the range 20-35GHz except for the California
nebula (NGC1499), which appears to have a high spinning dust peak
frequency of (50±17)GHz. The AME regions tend to be more spatially
extended than regions with little or no AME. The AME intensity is
strongly correlated with the sub-millimetre/IR flux densities and
comparable to previous AME detections in the literature. AME
emissivity, defined as the ratio of AME to dust optical depth, varies
by an order of magnitude for the AME regions. The AME regions tend to
be associated with cooler dust in the range 14-20K and an average
emissivity index, βd, of +1.8, while the non-AME regions are
typically warmer, at 20-27K. In agreement with previous studies, the
AME emissivity appears to decrease with increasing column density.
This supports the idea of AME originating from small grains that are
known to be depleted in dense regions, probably due to coagulation
onto larger grains. We also find a correlation between the AME
emissivity (and to a lesser degree the spinning dust peak frequency)
and the intensity of the interstellar radiation field, G0. Modelling
of this trend suggests that both radiative and collisional excitation
are important for the spinning dust emission. The most significant AME
regions tend to have relatively less ionized gas (free-free emission),
although this could be a selection effect. The infrared excess, a
measure of the heating of dust associated with HII regions, is
typically >4 for AME sources, indicating that the dust is not
primarily heated by hot OB stars. The AME regions are associated with
known dark nebulae and have higher 12µm/25µm ratios. The
emerging picture is that the bulk of the AME is coming from the
polycyclic aromatic hydrocarbons and small dust grains from the colder
neutral interstellar medium phase.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 187 98 *List of 98 candidate anomalous microwave emission
(AME) regions
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Note on table3.dat: Fitted parameters are based on the aperture photometry
(see Sect. 3.4).
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Region name (GLLL.ll+BB.bb)
14 A1 --- f_Name [*] * for regions that show significant
(>5σ) AME, except for those with a high
potential UCHII contribution (fmax>0.25)
15- 17 A3 --- n_Name [abc ] Detection method (1)
18 A1 --- l_theta Limit flag on theta
19- 21 F3.1 deg theta FWHM deconvolved size θ
23- 25 F3.1 deg e_theta ? rms uncertainty on theta
27- 32 F6.1 pc/cm6 EMff Effective emission measure integrated over
the aperture
34- 38 F5.1 pc/cm6 e_EMff rms uncertainty on EMff
40- 43 F4.1 10-5 tau250 [0/47] Dust optical depth at 250µm (4)
45- 48 F4.1 10-5 e_tau250 rms uncertainty on tau250
51- 54 F4.1 K Td [13/27] Dust temperature (4)
56- 58 F3.1 K e_Td rms uncertainty on Td
60- 63 F4.2 --- betad [1.3/2.4] Dust emissivity index βd (4)
65- 68 F4.2 --- e_betad rms uncertainty on betad
70- 73 I4 uK DTcmb CMB fluctuation temperature ΔTCMB
75- 77 I3 uK e_DTcmb rms uncertainty on DTcmb
79- 83 F5.1 10+20cm-2 Asp Anomalous microwave emission (AME) amplitude
85- 88 F4.1 10+20cm-2 e_Asp ? rms uncertainty on Asp
89 A1 --- n_Asp [+] + when Asp fixed at zero (see Sect. 3.5)
90- 93 F4.1 --- sigma [0.2/30]?=- AME significance (σAME)
95- 98 F4.1 GHz nusp ?=- Dust peak frequency νsp (2)
100-103 F4.1 GHz e_nusp ? rms uncertainty on nusp (2)
105-108 F4.2 --- fmax [0/6]?=- Ultra-Compact HII region contribution
fmax(UCHII)(=Smax(UCHII)/Sresid(28.4))
110-114 F5.2 --- G0 [0.2/11.2] G0, relative strength of the
Interstellar Radiation Field (IRSF)
(G0=1 corresponds to 1.2µW/m2)
116-119 F4.2 --- e_G0 rms uncertainty on G0
121-125 F5.1 Jy S28.4 AME residual flux density at 28.4GHz
(Sresid(28.4))
127-130 F4.1 Jy e_S28.4 rms uncertainty on S28.4
132-135 F4.1 10-4 Ratio Ratio of AME flux density at 28.4GHz to 100um
(3THz) flux density (Sresid24.8/S100um)
137-139 F3.1 10-4 e_Ratio rms uncertainty on Ratio
141-144 F4.2 --- chi2r [0/2.6] Reduced χ2
146-187 A42 --- Notes Molecular cloud name and notes
188-190 A3 --- r_Notes Reference for Notes (3)
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Note (1): Detection methods as follows:
a = Detected in bandmerged catalogue
b = Detected in component subtracted map
c = Previously known source from the literature
Note (2): Values for nusp and are only given if σAME>2.
Note (3): References in brakets as follows:
(1) = Planck Collaboration XX (2011A&A...536A..20P 2011A&A...536A..20P)
(2) = Genova-Santos et al. (2011ApJ...743...67G 2011ApJ...743...67G)
(3) = Finkbeiner et al. (2002ApJ...566..898F 2002ApJ...566..898F);
Dickinson et al. (2006ApJ...643L.111D 2006ApJ...643L.111D)
(4) = Dickinson et al. (2007MNRAS.379..297D 2007MNRAS.379..297D)
Note (4): the thermal dust emission is fitted with a modified back-body model:
Sd=2hc-2ν3.τ250(ν/1.2THz)β/[exp(hν/kTd)-1]
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History:
From electronic version of the journal
References:
Planck Collaboration, Paper I 2012A&A...543A.102P 2012A&A...543A.102P
Planck Collaboration, Paper II 2013A&A...550A.128P 2013A&A...550A.128P
Planck Collaboration, Paper III 2013A&A...550A.129P 2013A&A...550A.129P
Planck Collaboration, Paper IV 2013A&A...550A.130P 2013A&A...550A.130P
Planck Collaboration, Paper V 2013A&A...550A.131P 2013A&A...550A.131P
Planck Collaboration, Paper VI 2013A&A...550A.132P 2013A&A...550A.132P
Planck Collaboration, Paper VII 2013A&A...550A.133P 2013A&A...550A.133P
Planck Collaboration, Paper VIII 2013A&A...550A.134P 2013A&A...550A.134P
Planck Collaboration, Paper IX 2013A&A...550A.139P 2013A&A...550A.139P
Planck Collaboration, Paper X 2013A&A...550A.140P 2013A&A...550A.140P
Planck Collaboration, Paper XI 2013A&A...557A..52P 2013A&A...557A..52P
Planck Collaboration, Paper XII 2013A&A...557A..53P 2013A&A...557A..53P
Planck Collaboration, Paper XIII 2014A&A...561A..97P 2014A&A...561A..97P
Planck Collaboration, Paper XIV 2014A&A...564A..45P 2014A&A...564A..45P
Planck Collaboration, Paper XV 2014A&A...565A.103P 2014A&A...565A.103P
Planck Collaboration, Paper XVI 2014A&A...566A..54P 2014A&A...566A..54P
Planck Collaboration, Paper XVII 2014A&A...566A..55P 2014A&A...566A..55P
(End) Patricia Vannier [CDS] 25-Jul-2014