Polarization Studies with LLAMA:

Transcription

1 Polarization Studies with LLAMA: Probe of Magnetic Field Structure Antonio Mario Magalhães IAG Universidade de São Paulo 1

2 Collaborators: Polarimetry Group - IAG, U. São Paulo Aiara Gomes (Grad student) Nadili Ribeiro (Grad student) Undergrads: Marcelo Rubinho, Daiane Seriacopi, Cássia Fernandez & Tibério Ferrari Collaborators: Elisabete dal Pino (IAG) Diego Falceta-Gonçalves (USP) Antonio Pereyra (ON-RJ) Cláudia Rodrigues (INPE/DAS) Alex Carciofi (IAG) Marcelo Borges (ON-RJ) Armando Domiciano (Obs. Nice) 2

3 Other collaborators: Jean-Philippe Bernard & CESR team Caroline Bot, U. Strasbourg! ISM/PILOT, PLANCK! SMC Karen & Jon Bjorkman, U. Toledo John Wisniewski, U. Washington! Magellanic Cloud ISM, circumstellar disks Pris Frisch, U. Chicago B-G Andersson, SOFIA/USRA V. Piirola, U. Turku, Finland! Local ISM 3

4 Sky in the sub-mm Galactic Dust Emission B and grain alignment in expanding shells and fronts? Role of B in cloud collapse? 4

5 B-field influence on Star Formation Star formation models Magnetic field (B) influences collapse Measurements of B: Efeito Zeeman Rotação Faraday Polarização Interestelar! óptico/nir, sub-mm! Infall Large pseudo-disk Outflow B Jet Protostar Small accretion disk Valee (2004), ad. by Crutcher

6 B-field influence on Star Formation Observações com o Sub-milimeter Array (SMA)! Girart et al. (2006)! 345 GHz (0.877 mm=877!m)! resol. angular de 1.56 x0.99 (@ 85 deg)! resol. de B = 360 UA emissão em 877µm linhas de B (dados e modelo) 6

7 Polarization by ISM Dust Polarization arises from Dust grains B field aligned by ISM s Magnetic Field, B Polarization provides info on Dust properties! size distribution, composition adapted from Ponthieu, Lagache; B sky! B component projected on the sky 7

8 Polarization by ISM Dust Polarization arises from Dust grains B field aligned by ISM s Magnetic Field, B Polarization provides info on Dust properties! size distribution, composition B sky! B component projected on the sky adapted from Ponthieu, Lagache; In the Optical/NIR: PA Bsky In the Sub-mm: PA " Bsky 8

9 Polarization Operational definition of the Stokes parameters [I, Q, U, V] Consider the following filters that measure the different polarization states: F 0 I = F 0 Stokes vector: Q = F 1 - F 4 U = F 2 - F 5 V = F 3 - F 6 9

10 Polarization Operational definition of the Stokes parameters [I, Q, U, V] Consider the following filters that measure the different polarization states: Stokes vector: 2" F 0 I = F 0 " Q = F 1 - F 4 U = F 2 - F 5 V = F 3 - F 6 10

11 Polarization by ISM Dust B-field of the Galaxy from stellar (optical) polarization Mathewson & Ford

12 B-field from Polarization Chandrasekhar & Fermi method C & F (53)! Equipartition between kinetic & perturbed magnetic energies + isotropic rms velocity: 1 2 V LOS B2! B sky + δb 4πρ Falceta-Gonçalves et al. (08) δv los tan(δφ) Pereyra & Magalhaes 07 Polarization PA distributions! B estimates 12

13 Optical/IR Survey of ISM Polarization Conducted at IAG-USP LNA observatory (22 deg South) initially in V now at H (1.65!m) band! point sources & extended objects! Data to be reduced & become public Main Goal Improve our knowledge of:! Magnetic Field Structure of the Diffuse ISM! Ratio between random & uniform components of B! Scale Length, L, of the Magnetic Field 13

14 Optical/IR Survey of ISM Polarization Related, additional Goals Study the Magnetic Field using polarization: at high Galactic latitudes, through clouds and structures; across open clusters, for mapping the field on small scales; through nearby dark clouds; through Bok globules (in the IR) near the Sun, from the immediate neighborhood out to 300pc; 14

15 Collapsing Dark Clouds Magnetic Field in Dark Clouds B and grain alignment in expanding shells and fronts? Role of B in cloud collapse? Musca Dark Cloud Feitzinger & Stuve 84 15

16 Collapsing Dark Clouds Magnetic Field in Dark Clouds B and grain alignment in expanding shells and fronts? Role of B in cloud collapse? Musca Dark Cloud 16

17 Collapsing Dark Clouds Magnetic Field in Dark Clouds What is the role of B in cloud collapse? Mapping the Musca Dark Cloud 17

18 Collapsing Dark Clouds Magnetic Field in Dark Clouds What is the role of B in cloud collapse? Pereyra & Magalhaes 04 Mapping the Musca Dark Cloud Collapse along B! B ~ 0.03 mg mg! M cloud ~ 140 M 18

19 Collapsing Dark Clouds Does Polarimetry Map the Field? Optical Near IR (1.65µm)! Near IR Polarimetry confirms optical PA 19

20 Optical/IR Survey of ISM Polarization High Latitude Clouds Regions from COBE/DIRBE (Reach et al. 98) Hipparcos stars towards each cloud short + long exposures For 10 HLCs:! High-resolution spectra for the HIP stars! distance estimates to these clouds 24 HLCs observed thus far! 104 HIP stars 20

21 High Latitude Clouds Fields towards DIR Magnetic field along ISM filaments! Cassia Fernandez 21

22 MHD Turbulence Simulations! Supersonic, sub-alfvenic B on the plane of the sky Effects of B sky Falceta-Gonçalves, Gouveia Dal Pino 22

23 MHD Turbulence Simulations! Supersonic, sub-alfvenic B along l.o.s Effects of B rand Falceta-Gonçalves, Gouveia Dal Pino 23

24 Polarization of the CMB IAG - CESR/Toulouse collaboration Use of PLANCK satellite (2008) + PILOT balloon experiment + IAG-USP survey Planck Pilot Goals: Correct the cosmological observations Study dust & B-field of Interstellar Clouds 24

25 Optical Polarization by Dust SOUTH POL: Survey of the Polarized Southern Sky! Support: FAPESP! PI: Magalhães Goal: Polarimetric accuracy of 0.1% at V=15-16 First epoch: Sky South of Dec -15 Completed in ~ 2 years 25

26 SOUTH POL Telescópio Robótico de 80cm! TR-80S PI: C. M. de Oliveira Instalação: 2012 CTIO, Chile CCD:! EEV, 9k x 9k, 92mm! 2.0 graus quadrados (!)! =0>5&'9)'?$//0%6'+3'1.&'<&%3+%/0,-&'+3'1.&'=@:'2&;"#,' ' 8&%3+%/0,-&;'+3'2&;"#,' %<1=,+=1! )D(/)!3!>2431,1=! $74,1!:;471! 00)!33!L0DRHM!E2,-!*<,232V1>!23451!6+472,8! 0BB!?3!L.D/HM!E2,-!7232,1>!<1=9*=34?;1:! W3451!X+472,8!! B)P!QQ!! Y!B!S3!T!)D.(!4=;:1;!L>2431,1=M! ()P!QQ!! Y!0U!S3!T!)DR.!4=;:1;!L>2431,1=M! Z2:,*=,2*?! )DCP!!!! 26

27 SOUTH POL Polarimeter Prisma Savart de calcita io r -*-*_ '<_ 3,50 lil lfi il -+ll-- ll t-""" I ==[,* t- l_l rat 55.96to: 1 3,50*or { lt,rj/ 10 r- Str nn *f =t ob'i fi l Lâmina de meia-onda rrl --*l r--** 52,40 T--[-r], L_i_l 27

28 SOUTH POL Polarímetro Prisma Savart de calcita io r -*-*_ '<_ 3,50 lil lfi il -+ll-- ll t-""" I ==[,* t- l_l rat 55.96to: 1 3,50*or { lt,rj/ 10 r- Str nn *f =t ob'i fi l Lâmina de meia-onda rrl --*l r--** 52,40 T--[-r], L_i_l 28

29 SOUTH POL SOUTH POL combines Southern 80cm Robotic Telescope in Chile! funded by FAPESP Large field Imaging Polarimeter! 2.0 sq.deg. IAGPOL footprint Cassia Fernandez 29

30 SOUTH POL SOUTH POL combines Southern 80cm Robotic Telescope in Chile Large field Imaging Polarimeter! 2.0 sq.deg. South Pol footprint Cassia Fernandez 30

31 Polarization by ISM Dust Optical polarization works w/ low A V (1-5 mag)! Ex., outskirts of dark clouds B field Sub-mm polarization works w/ high Av (10-100)! Ex., central regions of dark clouds adapted from Ponthieu, Lagache; In the Optical/NIR: PA Bsky In the Sub-mm: PA " Bsky 31

32 Sub-mm Polarization from Bok Globules CB3 Basic data! 6.7x5.6 arcmin! d ~ 2.5 kpc! 2 embedded YSOs! intermediate mass star formation site YSO = Young Stellar Object star_and_planet_formation/ young_stellar_objects.html 32

33 Sub-mm Polarization from Bok Globules CB3! Ward-Thomson et al Polarization maps! optical! sub-mm! contours: 850!m (353 GHz) Stars near the border! PA opt! PA sub-mm Optical:! Av ~ Sub-mm:! N~10 22 cm -2! Av ~ 10 Obs: PAsub-mm girado de 90deg

34 Sub-mm Polarization from Bok Globules CB3! Ward-Thomson et al Polarization maps! optical! sub-mm! contours: 850!m (353 GHz) Stars near the border! PA opt! PA sub-mm Optical:! Av ~ Sub-mm:! N~10 22 cm -2! Av ~ 10 Obs: PAsub-mm girado de 90deg

35 Polarization by ISM Dust Optical polarization works w/ low A V (1-5 mag)! Ex., outskirts of dark clouds B field Sub-mm polarization works w/ high Av (10-100)! Ex., central regions of dark clouds adapted from Ponthieu, Lagache; Enter LLAMA! 35

36 B-field from Polarization Chandrasekhar & Fermi method Pereyra & Magalhaes 07! LLAMA line observations will provide gas dynamics! From Equipartition: 1 2 V LOS B2! B sky + δb 4πρ Falceta-Gonçalves et al. (08) δv los tan(δφ) Polarization PA distributions! B estimates 36

37 B-field influence on Star Formation Star formation models Magnetic field (B) influencia collapse Medidas de B: Efeito Zeeman Rotação Faraday Polarização Interestelar! óptico/nir, sub-mm! Infall Large pseudo-disk Outflow B Jet Protostar Small accretion disk We d need ALMA/ALMA+LLAMA Valee (2004), ad. by Crutcher

38 Polarimetry with LLAMA In summary: From Optical/NIR! B-field in the ISM & collapsing cloud periphery From LLAMA! B-field in the denser parts of the dark cloud From ALMA + LLAMA! B-field in cloud cores 38