Discussion topics brought forward by the Jan. 9 organizational meeting:


Abstract for 2 PM Jan. 10 talk by Abigail Stevens (Amsterdam):


Comparing origins of low-frequency quasi-periodic oscillations with spectral-timing


X-ray spectral-timing is a new field that seeks to investigate how matter behaves in strong gravitational fields. Observations suggest that different types of quasi-periodic oscillations (QPOs) are associated with different emitting-region geometries (e.g. disk-like or jet-like) in the innermost part of the X-ray binary, close to the neutron star or black hole. We developed a technique for phase-resolved spectroscopy of QPOs, and are applying it to Type B and Type C low-frequency QPOs from the black hole X-ray binary GX 339-4. On the QPO time-scale, we find that the energy spectrum changes not only in normalization, but also in spectral shape. We can quantify how the spectral shape changes as a function of QPO phase, and the two different QPOs show markedly different spectral changes. In our previous work, we inferred that the Type B QPO could be caused by a large-scale-height (i.e., jet-like) precessing region illuminating and heating overlapping azimuthal regions of the inner accretion disk. Preliminary results of the Type C QPO indicate that a small-scale-height (disk-like) precessing region may be responsible for the observed spectral changes.

This talk will feature results from this paper: https://ui.adsabs.harvard.edu/#abs/2016MNRAS.460.2796S/abstract

References to the AGN discs discussion on January 12, 2017

Absence of dwarf-nova type of outbursts in AGNs. http://www.aanda.org/articles/aa/pdf/2009/11/aa10928-08.pdf

Mircolensing size constraint review. Morgan et al. (2010) http://adsabs.harvard.edu/abs/2010ApJ...712.1129M
Note that the wavelength - radius relation should be R \propto \lambda^{4/3} (the opposite was written carelessly on the board)

Continuum reverberation mapping size. Edelson et al. (2015) http://adsabs.harvard.edu/abs/2015ApJ...806..129E

Similar results for more than 200 quasars in Pan-STARRS medium deep fields: Jiang et al. (2016) https://arxiv.org/abs/1612.08747

Possible effects of wind on SED. Laor & Davis (2014): http://adsabs.harvard.edu/abs/2014MNRAS.438.3024L

(BAL)QSO emission line EWs are inconsistent with unification based on standard disks:

Could the 1000A turn-over in AGN/QSO SEDs just be to due absorption in the IGM? Lusso+15

Slides from the protostellar disks discussion 2017 January 18 with Ruobing Dong

Slides from Steve Tobias/Geoffroy Lesur "Problems with Simulating Disks" talk.

Steve's bit (includes references for Dynamo bit and some slides on the Saturation of the GSF instability, which also relies on getting the small scales correct)

Discussion on variability in CVs on 2017 January 24 led by Christian Knigge.

Flicker noises in accretion disks. Lyubarskii, 1997. http://adsabs.harvard.edu/abs/1997MNRAS.292..679L

Testing the propagating fluctuations model with a long, global accretion disk simulation. Hogg & Reynolds, 2016. http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1512.05350

Discussion on protoplanetary disk winds on 2017 January 31 led by Xuening Bai

Wind theory paper, Bai et al. 2016: http://adsabs.harvard.edu/abs/2016ApJ...818..152B

General overview: Cabrit et al. 2011: http://adsabs.harvard.edu/abs/2011IAUS..275..374C

Constraining the wind launching radius, Anderson et al. 2003: http://adsabs.harvard.edu/abs/2003ApJ...590L.107A

Some (limited) observation papers:

Forbidden lines:
Hartigan et al. 1995: http://adsabs.harvard.edu/abs/1995ApJ...452..736H
Simon et al. 2016: http://adsabs.harvard.edu/abs/2016ApJ...831..169S

Large-scale CO outflow:
Klaassen et al. 2013: http://www.aanda.org/articles/aa/abs/2013/07/aa21129-13/aa21129-13.html
Bjerkeli et al. 2016: http://www.nature.com/nature/journal/v540/n7633/full/nature20600.html

Discussion on outflows from accreting compact objects on 2017 Feb 1 led by Christian Knigge

Outflows from accreting compact objects

Discussion on FU Ori outbursts on 2017 Feb 14 led by Lee Hartmann

Magnetic turbulence and thermodynamics in the inner region of protoplanetary discs (Hirose 2015): https://academic.oup.com/mnras/article-lookup/doi/10.1093/mnras/stv203

Discussion on Critical Observations on 2017 Feb 28 led by Christian KniggeIMG_0704.jpg

Discussion on Critical Simulations on 2017 Mar 1 led by Omer Blaes


Discussion on Ultraluminous X-ray Sources (especially those containing pulsating neutron stars) on 2017 March 2 led by Juri Poutanen


Discussion of 2015 outburst of the black-hole X-ray binary V404 Cyg on 2017 March 9 led by Phil Charles

A view of accretion-disc structure in various astrophysical contexts