Very happy to announce that we had our first meeting of the “Clube dos AGNs”. We discussed the following papers and you can find a few rough notes below.
Seth, A.: A Supermassive Black Hole in an Ultracompact Dwarf Galaxy, Nature [Rodrigo] Link for ars technica article and the Gemini press release (http://bit.ly/10l0rJF)
Very neat IFU Gemini North observations of an ultracompact dwarf galaxy. Velocity dispersion modeled and interpreted as BH mass 2e7 Msun, stellar mass 1e8 Msun. Black hole corresponds to 15% of the galaxy. Interpreted as a stripped galactic nucleus. Properties of bulge of original galaxy inferred by applying M-sigma to the resulting BH mass. Potential large population of such kind of objects around, which would contribute to the black hole mass density at low z. We discussed about the Schwarzschild — which I learned afterwards is the son of *the* Karl Schwarzschild –method for modeling, which apparently is very computationally intensive. Not clear what constraints the model gives no dark matter distribution.
“The black hole mass scale of classical and pseudo bulges in active galaxies”. de Luis Ho e Minjin Kim. Ap J 789, 17 (july/ 2014). [Steiner]
João gave a quick description of reverberation mapping methods for constraining black hole mass. Virial theorem (trivial theorem). Connection between sigma and BLR radius, both from observations. Indirect way of constraining the f factor in the mass determination, which captures the BLR geometry. João also told us the differences between pseudobulges and classical bulges (sersic parameter). Different formation process for pseudobulges? Different values of f for classical bulges (6) and pseudobulges (3). Some interesting questions raised by this paper:
- Is the structure of the BLR different depending on the type of bulge/host galaxy?
- might this be related to different accretion modes?
Weak point: uncertainty on M-sigma as applied to pseudobulges.
Juliana and Bete told us about the highlights of the Galapagos IAU Meeting. News about variability, more attention to time lags between radio and gamma. Mention of Emmanopoulos talk. Kellermann talk. Bete: AGN feedback, ALMA observations, mention of Nature and Science papers involving Morganti. 100 days delay between gamma and radio.
Some papers noted on our list but we didn’t have time to discuss
Will keep them here for future reference.
Observational appearance of inefficient accretion flows and jets in 3D GRMHD simulations: Application to Sgr A*. http://adsabs.harvard.edu/abs/2014arXiv1408.4743M
IAS15: A fast, adaptive, high-order integrator for gravitational dynamics, accurate to machine precision over a billion orbits. http://adsabs.harvard.edu/abs/2014arXiv1409.4779R
Time dilation measured at 40 percent of the speed of light—in the lab. ars technica. http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.113.120405
Magnetic Flux of Progenitor Stars Sets Gamma-ray Burst Luminosity and Variability. http://adsabs.harvard.edu/abs/2014arXiv1409.4414T
More papers and discussion next week! Stay tuned!