1. COLD FRONTS IN X-RAY RELAXED GROUPS
FABIO GASTALDELLO
INAF-IASF MILANO
UC IRVINE

2. OUTLINE / MOTIVATION
COLD FRONTS (see Simona’s Astrosiesta talk) AND DYNAMICAL STATE
COLD FRONTS IN THE RELAXED GROUP NGC 5044
THE CLASS OF COLD FRONTS IN RELAXED GROUPS: ANOTHER EXAMPLE IN IC 1860 …
Introduction with NFW and cosmological relevance of the c-M relation with current observational results
Lack of results in the group mass range which spurred the work I’m presenting here.
Method of analysis (bkg subtraction, potential approach to HE equation, care to addressing systematics)
Group results
Cosmological implications of the extended sample ranging from ellipticals to massive clusters (Buote et al. 2006)

3. COLD FRONTS IN CLUSTERS
IN MERGING CLUSTERS
IN RELAXED CLUSTERS
Markevitch & Vikhlinin 07

4. COLD FRONTS IN CLUSTERS
Ascasibar & Markevitch 06

5. COLD FRONTS IN CLUSTERS
Markevitch & Vikhlinin 07

6. HOW ABOUT GROUPS ?
EXAMPLES IN MERGING SYSTEMS, e.g. NGC 1404 IN FORNAX (Machacek+05)

7. COLD FRONTS IN NGC 5044
FIRST BRIEF MENTION OF A POSSIBLE COLD FRONT IN THE RELAXED GROUP NGC 5044 (BUOTE+02)

8. COLD FRONTS IN NGC 5044 MENDEL+08 STUDY OF 111 MEMBERS:
PECULIAR VELOCITY OF 150 km/s WRT THE MEAN VELOCITY

9. COLD FRONTS IN NGC 5044
GASTALDELLO+08:
arXiv

10. COLD FRONTS IN NGC 5044
350-80
GASTALDELLO+08:
arXiv

11. COLD FRONTS IN NGC 5044
GASTALDELLO+08

12. COLD FRONTS IN NGC 5044
GASTALDELLO+08

13. COLD FRONTS IN NGC 5044
GASTALDELLO+08

14. COLD FRONTS IN NGC 5044
DETECTION OF A SUBSTRUCTURE (99.9 %) AT 1.4 Mpc MENDEL+08

15. IC 1860 ONE SOURCE MIGHT JUST BE ODD, TWO ARE A CLASS
~ 70 MEMBERS FROM 2DF, AGAIN PECULIAR VELOCITY OF THE cD w/ 140 km/s

16. OK, BUT WHY DO WE CARE ?
STEPS TOWARDS A PRECISE CHARACTERIZATION OF THE DYNAMICAL STATE OF A CLUSTER/GROUP THANKS TO MULTI-LAMBDA OBSERVATIONS
Markevitch & Vikhlinin 07

17. OK, BUT WHY DO WE CARE ?
STEPS TOWARDS A PRECISE CHARACTERIZATION OF THE DYNAMICAL STATE OF A CLUSTER/GROUP THANKS TO MULTI-LAMBDA OBSERVATIONS