PoS(HEASA2019)018 h https://pos.sissa.it/ and P. Serra cdg G. Jozsa, cde f K. Thorat, ab D. Prokhorov, a A. Chen, a , ∗ [email protected] Speaker. The Circinus galaxy is aby composite kpc starburst/Seyfert scale galaxy outflows which along exhibitsstudy radio its the lobes minor physical inflated axis. nature offormation Its these activity proximity or outflows. (4 if Mpc) they We are makes investigate5 jets if arcsecond it from resolution they a an radio originate unique active observations, from galactic target whichof core. is nuclear to the in star The the Circinus MeerKAT observed array galaxy. range performs ofwill In the be arcminute this conducted lobes work, using a theaid multi-wavelength available in analysis MeerKAT the observations of understanding and the of Fermi-LATthe radio the data, star-formation origin lobe which driven of structures will Fermi these bubbles structures.both the in gamma-ray The the and results the Milky radio can bands Way, thenstructures. to which be determine have possible compared physical also to similarities between been these observed in ∗ Copyright owned by the author(s) under the terms of the Creative Commons Department of Physics, University of Pretoria The Inter-University Institute for Data Intensive Astronomy (IDIA), Department of Astronomy, GRAPPA, Anton Pannekoek Institute for Astronomy, University of Amsterdam c Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). 7th Annual Conference on High Energy28 Astrophysics - in 30 Southern August Africa 2019 - HEASA2019 Swakopmund, Namibia R. Ebrahim Multi-wavelength study of large-scale outflows from the Circinus galaxy Department of Physics and Electronics, RhodesPO University Box 94, Makhanda 6140, South Africa Private Bag X20, Hatfield 0028, South Africa University of Cape Town Argelander-Institut für Astronomie Auf dem Hügel 71, D-53121 Bonn,INAF- Germany Osservatorio Astronomico di Cagliari Via della Scienza 5, I-09047 SelargiusE-mail: (CA), Italy School of Physics, University of the1 Witwatersrand Jan Smuts Ave, Johannesburg, 2000, South Africa Science Park 904, 1098 XH Amsterdam,South The African Netherlands Radio Astronomy Observatory Black River Park, 2 Fir Street, Observatory, Cape Town, 7925, South Africa f e c g h a b d PoS(HEASA2019)018 ]. 4 R. Ebrahim ] to explain 7 ]]. 5 : In this model the lobes Starburst-driven galactic ] which possesses characteristics ]. The significant star-formation 1 3 AGN-driven jets ]. 7 1 ]. 2 ]. ]]. ] and Centaurus A which is the nearest AGN and has jets, 6 9 ]], NGC 3079 which like Circinus has lobes and presents 10 8 ]. 2 : The outflows result from supernova explosions in the core whose combined stellar winds Similar to the origin of radio lobes in Circinus, the origin of Fermi bubbles is still debated: The discovery of Fermi bubbles and the study of its origins demands the observation of other In the AGN (Active Galactic Nucleus) classification scheme Seyfert galaxies feature relatively A prominent feature of Circinus is the kpc radio lobe outflows along its minor axis. There Studying the lobes of Circinus in greater detail could provide a better understanding of these There is a similar type of kpc emission in our Milky Way known as the Fermi bubbles. They Starburst galaxies show very high star formation rates compared to normal galaxies. These The Circinus galaxy is a spiral galaxy at a distance of 4 Mpc [ radio lobes and diffuse emission [e.g.,[ Both the cocoon and the shell emit in the radio, X-ray, and gamma-ray bands [e.g.,[ radio emission from the Fermi bubbles whereoutwards these and particles radiate are transported via from the the synchrotronobserved galactic mechanism to plane have to a produce narrow the waist lobes. whichsupports is a These consistent star-formation bubbles with driven are a outflow also central model star-forming [ ring of gas and this both AGN and starburst characteristics [ AGN-driven or starburst-driven outflows. A cosmic ray model has been advocated [ galaxies that feature aAGN similar ejecta emission driven structure. radio lobes [e.g., Such [ galaxies include NGC 1068 which has low luminosity nuclei, and like other AGNs,Circinus are is powered classified by as supermassive a black Seyfert holes.narrow 2 The emission core core lines for of [ several reasons including the presence of characteristic are two models commonly used to explain the origins of these lobes: (i) emission models. 2.2 Studying Fermi bubbles were first discovered as gamma-ray emittingkpc above lobes and which below extend the from Galactic the plane Galactic [ centre about 8 of both Seyfert and starburst galaxies. 2. Why Circinus? 2.1 Studying the origin of radio lobes winds form a super-bubble which is observed asarise a radio from lobe. the (ii) flow ofenergy and jet momentum fluid this through flow can a drive strong a bow shock shock, that i.e. spreads the in shell, through a the cocoon. ambient gas With [ sufficient galaxies are ideal laboratoriesintergalactic to medium. study As star a formationbrightest consequence and type of II its its supernova feedback star in into formation the the activity, radio Circinus interstellar and hosts X-ray, and one SN1996cr of [ the Multi-wavelength study of large-scale outflows from the Circinus galaxy 1. Introduction rate, starburst characteristic emission lines (HIICircinus regions) are and indicators the of observed its nuclear starburst starburst nature ring [ in PoS(HEASA2019)018 R. Ebrahim , presenting an un- 2 ]. 2 Proposed structure of Circinus from Figure 2: ATCA observations [ ]. 2 11 [ 3 4.4 × ] propose the structure shown in Figure 2 shows the resultant image of the galaxy extracted from this data. 1 MeerKAT radio map of Circinus beam, a central frequency of 1.375 GHz 2 ATCA observations of Circinus [ Radio lobes are usually observed in elliptical galaxies. Unlike elliptical galaxies, spiral galax- The Milky Way is unusual in that it is a spiral galaxy with large outflows along with NGC We observe the radio lobes of Circinus and investigate its observational properties to study MeerKAT provides deeper and more sensitive images compared to the earlier studies of Circi- (Thorat et al., in preparation) with a 7.6 Figure 1: arcsec and in units of Jy/beam (1.3 arcsec/px). resolved core surrounded by a diffuse1.5 radio starburst kpc ring in and radio length lobes consistingsimilar which ATCA of are radio approximately a map is central shown plume in Figure (or a cocoon) and an edge brightened region. A ies feature a very denseThese interstellar smaller medium jets (ISM) mean making less it energy difficult is for being the fed into jets the to ISM1068, travel to NGC far produce 3079 out. lobes. and Circinus. TheseAGN galaxies with are their ideal environment candidates in to spiral investigatemuch galaxies. the closer, In interaction enabling of addition, the we study choose of to the study substructure Circinus of since its it lobes is 2.4 in better Research detail. objective lobe formation through a multi-wavelength analysis ofLAT these data. structures using MeerKAT These and Fermi- resultssimilarities will between these also structures. be compared to the Fermi bubbles to determine3. any Results physical 3.1 Spatial structure of radio lobes nus with ATCA. This meansmore that clearly, the allowing regions us the of opportunity differentvious to brightness efforts. analyse in new There Circinus information are which can 3.6in may be hours preparation). have of identified eluded Figure 1.4 pre- GHz MeerKAT data available for Circinus (Thorat et al., Multi-wavelength study of large-scale outflows from the Circinus galaxy 2.3 Studying radio lobed spiral galaxies PoS(HEASA2019)018 . 5 R. Ebrahim ) since MeerKAT 3 ]. This is usually interpreted as 6 . The localisation of these regions 1.4 GHz MeerKAT radio image of 4 Figure 4: Circinus with edge-brightened regions outlined (Thorat et al., in preparation). 3 ] in their studies of the bubbles in Circinus and Fermi 14 ) to investigate the potential of their detection in the VHE 6 ]. They investigated the possibility of a jet origin for the cocoons 12 ] and Kataoka et al. (2018) [ 13cm ATCA radio map of Circinus 13 ]. Another previously identified feature of the lobes of Circinus is its plumes. WeThis identified can these be compared to similar regions of enhanced gamma-ray emission found in Fermi bub- The bubbles in Circinus are also targets for gamma-ray telescopes. We modeled the broadband This effect has also been observed in X-ray observations of Fermi bubbles in which the edges We found a similar morphology when comparing the MeerKAT image to their ATCA image: From the MeerKAT image, we identified the bright, thin regions along the edges of the lobes, 11 Figure 3: [ regions from the MeerKAT image as the brightest regions inside each lobe,bles, as identified shown in as Figure ’cocoons’ [ shock waves. 3.2.2 Plumes Bubbles, respectively. emission of the lobes of Circinus (Figure but did not find sufficient supporting evidence. 3.3 Broadband emission of the lobes range. For this, weal. assumed (2013) a [ leptonic framework based on the approach taken by Hayashida et of the bubbles line up with features in the ROSAT X-ray maps [ is more precise compared to previous ATCA observations of Circinus (Figure a bright core region, a visibleand radio south-easterly galactic disk, directions. and radio There outflowsthose oriented observed were in in also the the north-westerly southern star-forming part regions of at the disk. similar locations3.2 such Comparisons as between Circinus’ lobes and Fermi bubbles 3.2.1 Edge-brightening to demonstrate the edge brightening effect shown in Figure Multi-wavelength study of large-scale outflows from the Circinus galaxy observations offer a higher sensitivity at a finer angular resolution. PoS(HEASA2019)018 3 − cm 10 − R. Ebrahim 10 × 5 . 1 8 = 10 N × 12.0 2000.0 1.0 . The X-ray upper limit from 6 Kataoka et al. (2018) 10 × 0 . 5 = 6 10 break × γ 1.0 4 5.0-10.0 1.0 SED model of Circinus’ lobes. Hayashida et al. (2013) Input parameters for SED modeling . Our model (shown in green) assumes 1 8 10 Figure 6: × 3.5 Table 1: 2000 1.0 Our Model ] and their corresponding radio data point were also used to constrain this 11 G) µ min max ( γ γ ]). Thus CTA observations of Circinus could also be fruitful in studying the physical B Parameter 16 1.4 GHz MeerKAT radio image of Circinus with plumes outlined (Thorat et al., in preparation). ];[ 15 According to our model, the lobes cannot be detected by Fermi-LAT but, there is potential for We modeled the spectral energy distribution (SED) assuming a broken power-law electron Figure 5: a detection by the southernlobed Cherenkov Telescope galaxies Array are (CTA-South). expected CTA to observations(e.g. better of [ resolve other the nuclearnature outflow of associated its gamma-ray lobes. emission (the number of electronsMingo per et unit al. volume) (2012) and [ model. distribution with energy equipartition betweeninput the parameters electrons shown in and Table the magnetic field and used the Multi-wavelength study of large-scale outflows from the Circinus galaxy PoS(HEASA2019)018 R. Ebrahim A large new ] and also help us better under- Radio continuum evidence for 2 . (1998) 1202 297 5 MNRAS , signal above the background emission. However, there was no σ (1977) 445. 55 ] re-analysed the GeV emission from Circinus based on 10 years of 17 A&A , galaxy in Circinus. nuclear outflow in the Circinus galaxy Guo et al. (2019) [ In modern gamma-ray telescopes, the finest angular resolution is about 5 arcmin which is Hayashida et al. (2013) studied the gamma-ray emission from Circinus using Fermi-LAT. We will conduct an independent temporal analysis of gamma-ray emission coming from the All these results could be used to provide support for either a jet, starburst or composite model This work is based on the research supported wholly/in part by the National Research Founda- The existing MeerKAT observations will allow us to perform a spectral analysis which could [1] K. C. Freeman, B. Karlsson, G. Lynga, J. F. Burrell, H. van Woerden, W. M. Goss et al., [2] M. Elmouttie, R. F. Haynes, K. L. Jones, E. M. Sadler and M. Ehle, signature of temporal variability in their study. insufficient to resolve the diskvariability of and the lobes Seyfert of nucleusray Circinus. may emission be in performed Instead the to of nucleus partially and a decompose diffuse spatial the components. analysis, observed gamma- a searchTheir observations for found a 7.3 Circinus galaxy by applying time-domainof algorithms, the e.g., Fermi-LAT data Bayesian and Blocks. anchance Given updated of that 10-year finding source 11 an catalog years AGN (4FGLDR-2) core are during now its available, low the or high statesin is explaining higher. the origin of these radio lobes. Acknowledgements tion of South Africa (Grant Numbers: 113833).telescope, provided This by work has the made South use African of Radiotelescope data Astronomy is from Observatory operated the (SARAO). by MeerKAT The the MeerKAT SouthNational African Radio Research Astronomy Foundation, Observatory, an which agency is of a the facility Department of the of Science and Technology. References stand the structure and origin ofin-depth, the emission comparisons in between each the region. lobes We of also Circinus intend and on Fermi performing bubbles further, 4.2 to search Gamma-ray for similarities. Fermi-LAT data using the 8-year2-year source source catalog catalog (4FGL) usedlower as by flux opposed which Hayashida is to consistent et the withalso al. the 4 found empirical years borderline relation (2013). for evidence of star-forming of datacompletely galaxies. temporal Their ruled and However, variability they out findings which either. include means an a AGN significantly jet origin cannot be provide new information on the ageing of electrons along the flow [ Multi-wavelength study of large-scale outflows from the Circinus galaxy 4. Future work 4.1 Radio PoS(HEASA2019)018 . DOI 758 Giant ]. MNRAS R. Ebrahim A&A ]. ]. , X-Ray , (2013) 131 Discovery of (2014) 64 Shocks, Seyferts, 779 Supernova 1996cr: 793 1310.3553 ApJ [ , 1005.5480 1301.0512 [ [ A&A Suzaku Observations of the , ]. , p. 050009, Jan, 2017, (2013) 57 ]. ]. (2013) 66 ]. 779 (2010) 1044 493 ]. 1905.04723 724 ApJ , ]. Natur ApJ , , 1011.1653 [ 0804.3597 [ Circinus Galaxy Revisted with 10 Years of 6 A Chandra X-Ray Study of NGC 1068. I. Observations The evolution of the large-scale emission in astro-ph/0104027 Giant Gamma-ray Bubbles from Fermi-LAT: Active [ 6th International Symposium on High Energy Gamma-Ray ]. Disentangling the gamma-ray emission of NGC 1068: The 1807.07375 . (2011) 1229 [ , in (2008) 1210 astro-ph/0304363 [ 412 (2001) 6 688 (2019) arXiv:1905.04723 [ -ray spectrum of the core of Centaurus A as observed with H.E.S.S. γ 556 Giant Metrewave Radio Telescope observations of NGC 3079 (1974) 513 A&A (2018) A71 The MNRAS , , ]. American Institute of Physics Conference Series (2003) 129 166 A&A 619 The Spectrum and Morphology of the Fermi Bubbles , 592 arXiv e-prints Models of extragalactic radio sources with a continuous energy supply from a astro-ph/0309373 A&A , [ , MNRAS ]. ]. A&A , , 1209.0348 , vol. 1792 of [ (2003) 977 1407.7905 1310.1913 of Extended Emission Diffuse X-Ray Emission across the Fermi Bubbles’ Edges and Fermi-LAT SN 1987A’s Wild Cousin? central object magnetized outflows from the centre of the Milky Way 346 (2012) 95 [ GeV Emission from the Circinus Galaxy[ with the Fermi Large Area Telescope case for AGN-driven galactic outflow Astronomy Fanaroff-Riley type I jets Galactic Nucleus Activity or Bipolar Galactic Wind? Emission from the Hot Interstellar MediumCentaurus and A Southwest Radio Lobe of the Nearby Radio Galaxy and the Supernova Remnant Connection: A Chandra Observation of the Circinus Galaxy Fermi-LAT Data [4] P. A. G. Scheuer, [5] P. Bordas, V. Bosch-Ramon and M. Perucho, [6] M. Su, T. R. Slatyer and D. P. Finkbeiner, [7] E. Carretti, R. M. Crocker, L. Staveley-Smith, M. Haverkorn, C. Purcell, B.[8] M. GaenslerA. et J. al., Young, A. S. Wilson and P. L. Shopbell, [9] J. A. Irwin and D. J. Saikia, [3] F. E. Bauer, V. V. Dwarkadas, W. N. Brandt, S. Immler, S. Smartt, N. Bartel et al., [15] H. E. S. S. Collaboration, [14] J. Kataoka, M. Tahara, T. Totani, Y. Sofue, Ł. Stawarz, Y. Takahashi et al., [16] A. Chen, S. Colafrancesco and N. Shafi, [12] M. Ackermann et al., [13] M. Hayashida, Ł. Stawarz, C. C. Cheung, K. Bechtol, G. M. Madejski, M. Ajello et al., [17] X.-L. Guo, Y.-L. Xin, N.-H. Liao and Y.-Z. Fan, Multi-wavelength study of large-scale outflows from the Circinus galaxy [10] R. P. Kraft, S. E. Vázquez, W. R. Forman, C. Jones, S. S. Murray, M. J. Hardcastle[11] et al., B. Mingo, M. J. Hardcastle, J. H. Croston, D. A. Evans, P. Kharb, R. P. Kraft et al.,