J/A+A/649/A32ivo://CDS.VizieR/J/A+A/649/A32doi:10.26093/cds/vizier.36490032CDSSanta-Maria M.G.Goicoechea J.R.Etxaluze M.Cernicharo J.Cuadrado S.2021-07-05T12:00:47Z2021-05-06T07:29:00ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frinterstellar-mediummolecular-cloudsWe present 168 arcmin^2^ spectral images of the Sgr B2 complex taken with Herschel/SPIRE-FTS. We detect ubiquitous emission from CO (up to J=12-11), H2O 2_1,1_-2_0,2_, [CI]492, 809GHz, and [NII] 205um lines. We also present maps of the SiO, N_2_H^+^, HCN, and HCO^+^ emission obtained with the IRAM30m telescope. The cloud environment dominates the emitted FIR (80%), H_2_O 752GHz (60%) mid-J CO (91%), and [CI] (93%) luminosity. The region shows very extended [NII] emission (spatially correlated with the 24 and 70um dust emission). The observed FIR luminosities imply G_0_~10^3^. The extended [CI] emission arises from a pervasive component of neutral gas with n_H_~10^3cm^-3^. The high ionization rates, produced by enhanced cosmic-ray (CR) fluxes, drive the gas heating to T_k_~40-60K. The mid-J CO emission arises from a similarly extended but more pressurized gas component (P_th_/k~10^7^K/cm^3^). Specific regions of enhanced SiO emission and high CO-to-FIR intensity ratios (>10^-3^) show mid-J CO emission compatible with shock models. A major difference compared to more quiescent star-forming clouds in the disk of our Galaxy is the extended nature of the SiO and N_2_H^+^ emission in Sgr B2. This can be explained by the presence of cloud-scale shocks, induced by cloud-cloud collisions and stellar feedback, and the much higher CR ionization rate (>10^-15^s^-1^) leading to overabundant H_3_^+^ and N_2_H^+^. Hence, Sgr B2 hosts a more extreme environment than star-forming regions in the disk of the Galaxy. As a usual template for extra- galactic comparisons, Sgr B2 shows more similarities to ultra luminous infrared galaxies such as Arp 220, including a "deficit" in the [CI]/FIR and [NII]/FIR intensity ratios, than to pure starburst galaxies such as M82. However, it is the extended cloud environment, rather than the cores, that serves as a useful template when telescopes do not resolve such extended regions in galaxies.2021A&A...649A..32Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/649/A32CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/482/179 : Interferometric study of SgrB2(N) (Belloche+, 2008)J/A+A/559/A47 : Sgr B2(N) and Sgr B2(M) IRAM 30m line survey (Belloche+, 2013)J/A+A/604/A6 : SgrB2 ALMA continuum and spectral index (Sanchez-Monge+, 2017)J/A+A/610/A10 : Sgr B2 los molecular absorption line spectra (Corby+, 2018)J/A+A/633/A120 : SgrB2(M) ^13^CCC and C^13^CC spectra (Giesen +, 2020)J/A+A/641/A160 : Hot aminoacetonitrile in Sgr B2 (Melosso+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/649/A32https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/649/A32http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/649/A32https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/649/A32https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/649/A32http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/649/A32GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/649/A32/list (List of line surface brightness images)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/649/A32/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/649/A32/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/649/A32/list?GETtext/xml+votable180.050000true266.83542-28.3850.0055555555555555566/28830https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/649/A32?format=asciidefaultJ/A+A/649/A32/listList of line surface brightness imagesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainsizeSize of ASCII fileKibytephys.size;meta.fileintFileNameName of ASCII filemeta.id;meta.filecharTitleTitle of the ASCII filemeta.title;meta.file