Post on 18-Mar-2019
How do you do a summary talk?
o Gradual sense of panic building for last month
o Then it struck me: workshops should be about answering questions
o So I wrote down some key questions:n What are ULXs?n How does super-Eddington accretion work?n What’s the effect of a ULX on its environment?
Thursday 16th June 2016 Tim Roberts - Summary talk 2
Firstly: an apology
o I can’t mention all the talks due to time limitations.
o If I’ve missed yours out it’s no comment on its contents(!), and I apologise profusely. Really. Particularly if your talk is this morning as I’ve (mostly) written this last night.
o Quality of figures may be poor (screen grabs)
Thursday 16th June 2016 Tim Roberts - Summary talk 3
Evidence for super-Edd ULXs?o Motch talk – P13o Spectra, light curve
modelling & Roche lobe constraints imply MBH < 15 M¤ & LX > Ledd
o Show ultraluminousspectra when super-Eddingtonn By extension most ULXs!
Thursday 16th June 2016 Tim Roberts - Summary talk 4
What are ULXs?
Chandra 2003
XMM 2013
kTin ~ 0.2 keV
kTe ~ 2 keV
diskbb + comptt
Cf. Middleton, Bachetti talks
Other optical mass functions?o Fabrika – spectra of
ULXs very similaro Described by SCAD
models; can’t see secondary star features
o Except for faintest (MV ~ -4) that have F/G-like spectra
Thursday 16th June 2016 Tim Roberts - Summary talk 5
NIR mass functionso Lopez/Heida – IR
c’parts less likely to be disc-dominatedn Better for mass fnn Tho’ periods long
o 47 NIR c’partsfound; 23 RSGs
o Initial spectra for 6; 3 RSGs
Thursday 16th June 2016 Tim Roberts - Summary talk 6
Can rule out short period, massive BHs from lack of RV change in 1 year for
J0047 in NGC 253 (Heida)
Proportion of ULXs that are IMBHs?o Webb – HLX-1 remains poster child for
IMBHs, but as a class they’re rareo Other candidate IMBHs: M51 X-7, CXO
J1225, NGC 2276 3c…o Zolotukhin – 16/98 new HLX candidates likely
bona fide (but which ones? Why found preferentially in spirals?)
o Wolter – 3 candidates from ring galaxieso Find new IMBHs in TDEs/small galaxy nuclei?
Thursday 16th June 2016 Tim Roberts - Summary talk 7
What are ULXs?
Any other underlying populations?o At least one NS
(Bachetti et al. 2004, opposite)
o Pintore talk – can’t exclude simple phenomenological NS models for NGC 1313 X-1
o Wictorowicz – extreme mass transfer rates, even in NS binaries
Thursday 16th June 2016 Tim Roberts - Summary talk 8
What are ULXs?
Physics of accretion flow (models)o All supercritical
accretion models converging on same structure
o Ohsuga/Mineshige – funnels, clumpy outflows, Poutflow = Lrad
Thursday 16th June 2016 Tim Roberts - Summary talk 9
How does super-Edd accretion work?
Physics of accretion flow (data)
o Middleton: big picture spectral-variability characteristics are consistent with funnel models with clumpy winds
Thursday 16th June 2016 Tim Roberts - Summary talk 10
Luangtip et al. (2016)
o Swift spectra for Ho IX X-1 stacked by flux and hardness – evidence for precession
Thursday 16th June 2016 Tim Roberts - Summary talk 11
Note precession in SS433
(Fabrika 2004); also highly
likely in P13 (Motch talk),
NGC 1313 X-1 (Middleton
talk), NGC 4395 (Vinokourov et
al. 2016)…
Lsoft goes as mdot; Lhard as mdot2
Disc-like spectra at highest LX
o Seen in Ho IX (Luangtip et al 2016, Walton et al. 2014), NGC 1313 X-2 (Pintore & Zampieri2012), NGC 1313 X-1 (Yoshida talk) – hard component beamed and downscattered in funnel?
Thursday 16th June 2016 Tim Roberts - Summary talk 12
From Yoshida
talk
From Sutton et al (2013)
BDHULSULHigh absorption
X-ray – optical properties from SCAD
Thursday 16th June 2016 Tim Roberts - Summary talk 13
Vinokourov talk
Note other models for optical emission – Ambrosi talk
Link with sub-Edd BHBs?o Kubota: possible similarities in spectral shape
between VHS and ULXso Shidatsu: GRO J1655 ultrasoft outburst shows
Compton-thick wind (very like ULXs)o Sutton: discs in BHBs at 0.1 Eddington also
appear broad (next slide)n Could mean BD ULXs are MsBHs (40 – 90 M¤) at
0.1-0.3 Eddingtonn Also plausible we don’t understand disc physics –
why are discs broad at 0.1 Eddington?Thursday 16th June 2016 Tim Roberts - Summary talk 14
How does super-Edd accretion work?
Evidence for outflows/winds?
Thursday 16th June 2016 Tim Roberts - Summary talk 16
How does super-Edd accretion work?
Pinto talk & Nature
paper
Also optical spectra
(Fabrika, Vinokourov)
What about jets?
o Koerding – scaling XRB cores to nearby galaxies: undetectable by SKA (but lobes up to 103 times brighter?)
o But IMBHs more radio-bright – get mass using fundamental plane
Thursday 16th June 2016 Tim Roberts - Summary talk 17
Jets in IR?
Thursday 16th June 2016 Tim Roberts - Summary talk 18
Dudik et al. (submitted) –
Spitzer detection.
Bright, variable jet or circumbinary
disc?JWST science?
Where do ULS fit?o Feng – part of UL
state (SSUL regime) – highest accretion rates?n NGC 247 ULX
transit SUL to SSULn But properties could
possibly be described by wind model (me)
Thursday 16th June 2016 Tim Roberts - Summary talk 19
How does super-Edd accretion work?
ULXULS
M83ULXM81ULS
From Roberto’s talk
ULSo Liu – M101 ULX1 is
classic ULS – has relativistic baryonic jets, stellar-mass BH (Nature papers) –super-Eddington!
o L ~ T-2: can’t be discs (also Urquhart & Soria etc)
Thursday 16th June 2016 Tim Roberts - Summary talk 20
Where are they found?o Many ULXs located near star formation (Swartz talk)
o Relationship: LX/1039 erg s-1 ≈ 2-6 × SFR (M¤ yr-1)o More ULXs seen in low metallicity galaxies (Brorby,
Mapelli) n Bigger BHs; more HMXB formationn Better survival rate of CE phase
Thursday 16th June 2016 Tim Roberts - Summary talk 21
Effect of ULX on its environment?
How do they affect environment?o Pakull – LX ~ Lmech
o Swartz – flat XLFs so few ULXs dominate LXfrom whole galaxy. n 71% of flux from ULXs (Brorby)n Their spectral shape important
o Brorby – large mean free path means X-rays escape early galaxies, warm IGM, delay re-ionisationn Quench SF in dwarf galaxies? Affect their
evolution mechanically? (Cf. missing dwarfs problem)Thursday 16th June 2016 Tim Roberts - Summary talk 22
Effect of ULX on its environment?
Does this change over cosmic time?o Brorby – lower metallicity
at higher z – more ULXs!n Missed by surveys due to
curvatureo Lehmer – LHMXB/SFR ≈
(1+z)o HMXB > AGN @ z > 5o Mechanical & radiative
ULX feedback important!
Thursday 16th June 2016 Tim Roberts - Summary talk 23
Effect of ULX on its environment?
Open questions
o Lags, QPOs (if real…)
Thursday 16th June 2016 Tim Roberts - Summary talk 24
X-ray/optical in Ho IX X-1 (Zampieri talk)
X-ray lags (Hernandez-Garcia et al. 2015)
Exciting new thingso Super-Eddington
neutron star simulations (Takahashi & Mineshige)
o Emitted power: Rotating BH > NS > non-rotating BH
Thursday 16th June 2016 Tim Roberts - Summary talk 26
BH: L > LEddNS: L ~ LEdd
Mag. NS: L ≈ LEdd(Ω/2π)
Exciting new things (2)o 2 adjacent ULXs in
M51 show eclipses! (Urquhart talk)
o But have different propertiesn ULX1 in SUL regime
& radio jet, optical nebula like SS433
n ULX2 in BD regime & bubble nebula?
Thursday 16th June 2016 Tim Roberts - Summary talk 27
ULX1hardsoft
ULX2
Exciting new things (3)
0 20 40 60 80 100 120 140 160 180
O1 upper limits
rateLIGO
BH-BHonly
M1
Thursday 16th June 2016 Tim Roberts - Summary talk 28
Belczynski –new LIGO detections
(23+13 M¤, 8+14 M¤).ULXs as
progenitors? Or different population?
What else did we learn?o Strasbourg is lovely;
but it rains a loto If you’re flying KLM,
check in as early as possible
o At the conference dinner, it’s not always good to sit in the middle of a lively debate…
Thursday 16th June 2016 Tim Roberts - Summary talk 29