Re-fuelling the Milky Way

Transcription

1 Re-fuelling the Milky Way From single clouds to the full sky Daniel Lenz Supervisor: PD Dr. Jürgen Kerp Argelander-Institut für Astronomie September 30th, 2013 Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

2 Problem Motivation University of Notre Dame Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

3 Probes of interaction Motivation Neutral hydrogen Deceleration of gas Positional (anti-) correlation Dust (far-infrared) Altered grain size distribution Heating & ionization Combination Altered ratio points towards dark gas Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

4 Effelsberg-Bonn H i Survey (EBHIS) Data EBHIS, Kerp et al. (2011) Full-sky survey of the northern hemisphere Galactic and extragalactic survey in parallel Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

5 Effelsberg-Bonn H i Survey (EBHIS) Data 0 h 21 h 3 h Started in 2008 Fully automated data-reduction (Winkel et al. 2010) (Almost) finished as of today 18 h 60 6 h 15 h h 9 h Courtesy B. Winkel Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / log(nhi[cm 2 ])

6 Complex C v LSR km/s Galactic latitude NHI [10 20 cm 2 ] Galactic longitude 80.0 Originates from IGM or satellite galaxy (Richter 2012) Inflow of 0.2 M yr 1 (Wakker et al. 2007) Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

7 Hydrogen column density Galactic latitude HVC: 180 v LSR km/s 90 IVC: 52 v LSR km/s NHI [10 20 cm 2 ] Galactic longitude Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

8 Hydrogen column density Galactic latitude HVC: 180 v LSR km/s 90 IVC: 52 v LSR km/s NHI [10 20 cm 2 ] Galactic longitude Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

9 Position-velocity diagram 2.4 vlsr [km s 1 ] b = 55.8 b = T [K] Galactic longitude Galactic longitude Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

10 Dust at 350 µm Galactic latitude Galactic longitude MJy sr 1 Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

11 Dust-to-gas ratio at 350 µm Galactic latitude Galactic longitude DGR [10 20 MJy sr 1 cm 2 ] Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

12 Pixelbased correlation a = 0.31 ± 0.04 b = 0.21 ± I350 µm [MJy sr 1 ] log(number of data points) NHI [10 20 cm 2 ] 0.0 I 350 = a 350 N H + b 350 Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

13 Pixelbased correlation a = 0.31 ± 0.04 b = 0.21 ± I350 µm [MJy sr 1 ] log(number of data points) NHI [10 20 cm 2 ] 0.0 I 350 = a 350 N H + b 350 N H = N H i + N H ii + 2 N H2 Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

14 Pixelbased correlation a = 0.31 ± 0.04 b = 0.21 ± I350 µm [MJy sr 1 ] log(number of data points) NHI [10 20 cm 2 ] 0.0 I 350 = a 350 N H + b 350 N H = N H i + N H ii + 2 N H2 Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

15 Molecular hydrogen Galactic latitude NH2 [10 20 cm 2 ] Galactic longitude Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

16 Conclusion Summary & outlook Hypothesis: has been shaped by the impact of a HVC EBHIS, IRIS and Planck confirm previous studies But open questions remain: Arc of enhanced DGR, HVC features overlap Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

17 Conclusion Summary & outlook Hypothesis: has been shaped by the impact of a HVC EBHIS, IRIS and Planck confirm previous studies But open questions remain: Arc of enhanced DGR, HVC features overlap Larger, statistical approach can be used to study entire complexes Better understanding of H i-dust correlations Full Planck & EBHIS data available in final version Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

18 Rotated position-velocity diagram Galactic latitude (1) (3) (2) NHI [10 20 cm 2 ] vlsr [km s 1 ] vlsr [km s 1 ] T [K] Galactic longitude vlsr [km s 1 ] Offset Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

19 Dust-to-gas ratio at 100 µm 2.0 Galactic latitude DGR [10 20 MJy sr 1 cm 2 ] Galactic longitude Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

20 Renzogram Galactic latitude vlsr [km s 1 ] Galactic longitude Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

21 60-to-100 micron 0.54 Galactic latitude I60/I Galactic longitude Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

22 EBHIS und GASS Galactic latitude log(nhi[cm 2 ]) Galactic longitude 20.0 Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

23 Spektrum 5 4 IVC v 0 = 49.0 ± 0.6 km s 1 FWHM = 7.6 ± 1.9 km s 1 T [K] local gas HVC v LSR [km s 1 ] v LSR [km s 1 ] Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

24 Staubtemperatur Galactic latitude K Galactic longitude Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

25 HVC Himmel Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

26 Planck Bänder Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13

27 Planck CO Daniel Lenz (AIfA) Re-fuelling the Milky Way September 30th, / 13