Radio recombination lines: the synergy between a big dish and - PowerPoint PPT Presentation

Radio recombination lines: the synergy between a big dish and dipoles Pedro Salas The Big Impact of a Big Dish: Science with the Effelsberg 100-m telescope Bonn, Germany, 20 February 2018 With support from RadioNet and NWO

Assembly of molecular clouds CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO HI HI HI HI HI HI HI HI HI HI HI HI HI HI HI HI HI Moriarty-Schieven

Interaction of stars and their environment Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X ESA/Herschel/PACS/SPIRE/HOBYS Consortium

The power of RRLs 0 . 000 − 0 . 002 − 0 . 004 78 MHz 54 MHz 30 MHz C α (438) C α (496) C α (601) 0 . 000 − 0 . 002 ◮ Mainly from carbon and hydrogen. − 0 . 004 73 MHz 49 MHz 24 MHz C α (448) C α (510) C α (645) τ α (Optical depth units) τ α (Optical depth units) τ α (Optical depth units) τ α (Optical depth units) τ α (Optical depth units) τ α (Optical depth units) τ α (Optical depth units) τ α (Optical depth units) τ α (Optical depth units) τ α (Optical depth units) τ α (Optical depth units) τ α (Optical depth units) τ α (Optical depth units) τ α (Optical depth units) τ α (Optical depth units) τ α (Optical depth units) τ α (Optical depth units) τ α (Optical depth units) 0 . 000 − 0 . 002 ◮ Change in line properties with frequency − 0 . 004 68 MHz 45 MHz 20 MHz constrains the gas physical properties. C α (459) C α (527) C α (689) 0 . 000 − 0 . 002 ◮ Low frequency emission from carbon − 0 . 004 64 MHz 41 MHz 17 MHz C α (467) C α (542) C α (731) traces cold diffuse gas ( n H ∼ 100 cm − 3 , 0 . 000 − 0 . 002 T ∼ 100 K). − 0 . 004 60 MHz 38 MHz 14 MHz C α (477) C α (559) C α (782) ◮ Hydrogen traces warm ionized gas. 0 . 000 − 0 . 002 − 0 . 004 57 MHz 35 MHz 11 MHz C α (485) C α (575) C α (843) − 50 0 50 − 80 0 80 − 250 0 250 500 Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 ) Radio velocity ( km s − 1 )

The power of RRLs C α frequency (MHz) 816.0 242.0 102.0 52.0 30.0 19.0 13.0 15 T e = 85 K n e = 0 . 04 cm − 3 T e = 85 K n e = 0 . 05 cm − 3 10 T e = 85 K n e = 0 . 03 cm − 3 Integrated optical depth (Hz) 5 0 25% variation in n e . − 5 − 10 − 15 200 300 400 500 600 700 800 Principal quantum number Oonk+2017

The power of RRLs C α frequency (MHz) 816.0 242.0 102.0 52.0 30.0 19.0 13.0 15 T e = 85 K n e = 0 . 04 cm − 3 T e = 105 K n e = 0 . 04 cm − 3 10 T e = 65 K n e = 0 . 04 cm − 3 Integrated optical depth (Hz) 5 0 25% variation in T e . − 5 − 10 − 15 200 300 400 500 600 700 800 Principal quantum number Oonk+2017

The power of RRLs 12 CO(2-1) 21 cm HI 2 . 5 2 . 5 ∆ δ (arcmin) 0 . 0 0 . 0 − 2 . 5 − 2 . 5 2 . 5 2 . 5 0 . 0 0 . 0 − 2 . 5 − 2 . 5 2 . 5 2 . 5 0 . 0 0 . 0 − 2 . 5 − 2 . 5 2 . 5 2 . 5 0 . 0 0 . 0 − 2 . 5 − 2 . 5 2 . 5 2 . 5 0 . 0 0 . 0 − 2 . 5 − 2 . 5 ∆ α (arcmin) Projected distance on the sky @3.16 kpc (pc) 4.6 5.4 6.1 6.9 7.7 8.4 9.2 1 . 2 12 CO(2 − 1) Normalized optical depth/intensity 18 cm-OH 1 . 0 C268 α C539 α 0 . 8 0 . 6 0 . 4 0 . 2 HPBW 0 . 0 300 350 400 450 500 550 600 Distance along slice (arcsec) Salas+2018

Interaction of stars and their environment Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X Cygnus X ESA/Herschel/PACS/SPIRE/HOBYS Consortium

The relation between ionized and neutral gas Sensitive observations with a 100 m single dish 40 40 Radio velocity w.r.t. H166 α (km s − 1 ) − 200 − 100 0 0 0 H 166 α 0 . 004 0 . 003 ∆ δ (arcmin) Optical depth − 40 − 40 C 166 α 0 . 002 40 40 0 . 001 0 . 000 0 0 0 100 200 Radio velocity w.r.t. C166 α (km s − 1 ) − 40 − 40 40 40 0 0 − 40 − 40 ∆ α (arcmin) Thanks to B. Winkel

The relation between ionized and neutral gas The LOFAR perspective 3 ◦ 3 ◦ 2 ◦ 2 ◦ 1 ◦ 1 ◦ b 0 ◦ 0 ◦ − 1 ◦ − 1 ◦ 76 ◦ 76 ◦ 78 ◦ 78 ◦ 80 ◦ 80 ◦ 82 ◦ 82 ◦ ℓ Oonk+in prep.

The relation between ionized and neutral gas The LOFAR perspective 3 ◦ 3 ◦ 2 ◦ 2 ◦ 1 ◦ 1 ◦ b 0 ◦ 0 ◦ − 1 ◦ − 1 ◦ 76 ◦ 76 ◦ 78 ◦ 78 ◦ 80 ◦ 80 ◦ 82 ◦ 82 ◦ ℓ Oonk+in prep.

The synergy between the 100 m dish and LOFAR C α frequency (MHz) 816.0 242.0 102.0 52.0 30.0 19.0 2 T e = 95 K n e = 0 . 03 cm − 3 T e = 10 K n e = 0 . 1 cm − 3 1 Integrated optical depth (Hz) Absorption 0 Emission − 1 − 2 − 3 200 300 400 500 600 700 Principal quantum number

Summary ◮ The ISM is a complex system, and observations across the electromagnetic spectrum are needed in order to understand it. ◮ RRLs at different frequencies can be used to study the density structure of the ISM. ◮ A combination of Effelsberg and LOFAR allows for an accurate determination of the gas physical conditions.