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AGNs in the Netherlands

AGNs in the Netherlands

We are happy to announce the programme of the first (since a long time at least) meeting of AGN researchers in the Netherlands. The meeting will happen on Monday, 8 July 2019, at Astron, Dwingloo with this preliminary programme:

  • 11.00 – 12.00
    • Leo Burtscher (Leiden): Introduction
      • The AGN landscape in the Netherlands and what can we learn from each other?
    • Round-the-table introduction
    • Raffaela Morganti (Astron/Groningen): Impact of radio jets: the ALMA view
  • 12.00 – 13.00: Lunch break
  • 13.00 – 14.30:
    • Violeta Gámez Rosas (Leiden): AGNs with MATISSE
      • Interferometry in the mid infrared benefits from several advantages for the study of the cores of AGNs, namely optimum access to the innermost dusty regions that lie very close to the central blackhole and a much higher resolution compared to single dish telescopes. Already with MIDI the old model of the dusty toroidal structure was challenged by unveiling substantial extended IR emission in the most unexpected directions. MATISSE, the latest instrumentation in this field, expands the reach of MIDI further into and beyond the mid-IR to the L and M bands, adds more spectroscopic potential and aims at fully exploiting multiple-baseline interferometry with the VLTI allowing, for the first time, image reconstruction. This talk describes MATISSE and the first results from the commissioning data.
    • Turgay Çağlar (Leiden)
    • Davide Lena (SRON/Utrecht): Radio jets and equatorial outflows?
      • Optical integral field spectroscopy has opened a new window on the inner kiloparsec of galaxies. Our observations of the ionised gas have shown the existence of a puzzling and unexpected kinematical feature: a region of enhanced velocity dispersion in a plane approximately perpendicular to radio jets and radio extensions, seemingly the plane of the AGN torus. The spatial extent of the “equatorial velocity-dispersion enhancements” (EVDE) is often sharply defined, and observed to extend over about 100 – 200 pc either side from the nucleus. Within this region, emission lines display complex profiles, suggesting the coexistence of multiple kinematical components. When feasible, detailed studies suggest the presence of ionised gas in rotation and/or outflow in a plane perpendicular to the axis of the radio jet. In this talk I will present an overview of our results and possible interpretations.
  • 14.30 – 15.00: Coffee break
  • 15.00 – 16.30
    • Nika Jurlin (Groningen): The life cycle of radio galaxies
    • Aleksandar Shulevski (Amsterdam): Case studies of AGN plasma ageing in two different environments
      • The cycling of AGN activity leaves different morphological imprints depending on the AGN duty cycle as well as on the environment of the host galaxy. I will showcase the LoTSS view of 3C 236, an active giant radio galaxy located in a group environment with plasma ageing evident in its lobes, and Abell 1318, a curious remnant hosted in a galaxy cluster, hinting at a complex activity history. Contrasting the remnant properties, I will discuss the context of these objects in the framework of what we can infer from observations and the contribution of low frequency data sets.
    • Suma Murthy (Groningen): HI in radio AGNs: A study at high redshifts
      • It is believed that active galactic nuclei (AGNs) affect the evolution of their host galaxies. HI-21cm absorption associated with the hosts of radio-loud AGNs is a powerful tool probe of the effect of radio AGNs on cold gas. Various associated HI absorption studies at low redshifts (z < 0.25) have found that the detection rate of HI is higher in compact (young or restarted) AGNs than the extended (old) ones. Further, the effect of radio AGNs on cold gas has been found to depend on the phase of AGN activity, with the impact being maximum when the AGN is young and powerful. However, we lack similar insights into the incidence of HI and the conditions of cold gas in different AGN classes as we go higher in redshifts. This is because most of the studies at higher redshifts have focused only on specific AGN classes (compact, flat-spectrum AGNs).We have searched for associated HI absorption in a sample of ultra steep spectrum radio galaxies at z > 2. I will present results from this search aiming to probe the redshift dependence of HI detection rate and other absorber properties.
  • 16.30 – 17.00: wrap-up
  • 18.00 – 20.00: dinner at Bospub
  • 21.05: Train connection from Hoogeveen arriving at 22.41 (Utrecht), 23.06 (Nijmegen), 22.53 (Amsterdam), 23.13 (Leiden)

The talk format is 15 min (talk) + 15 min (discussion) except for MSc and beginning Ph.D. students who can briefly present their project in 5 min.

For questions related to the event, please contact Nika Jurlin or Leo Burtscher.