The flux ratio of the [OIII] 5007,4959 lines in AGN: Comparison with theoretical calculations

By taking into account relativistic corrections to the magnetic dipole operator, the theoretical [OIII] 5006.843/4958.511 line intensity ratio of 2.98 is obtained. In order to check this new value using AGN spectra we present the measurements of the flux ratio of the [OIII] 4959,5007 emission lines for a sample of 62 AGN, obtained from the Sloan Digital Sky Survey (SDSS) Database and from published observations. We select only high signal-to-noise ratio spectra for which the line shapes of the [OIII] 4959,5007 lines are the same. We obtained an averaged flux ratio of 2.993 +/- 0.014, which is in a good agreement with the theoretical one.Comment: Accepted for publication in the MNRA

The intrinsic Baldwin effect in broad Balmer lines of six long-term monitored AGNs

We investigate the intrinsic Baldwin effect (Beff) of the broad H$\alpha$ and H$\beta$ emission lines for six Type 1 active galactic nuclei (AGNs) with different broad line characteristics: two Seyfert 1 (NGC 4151 and NGC 5548), two AGNs with double-peaked broad line profiles (3C 390.3 and Arp 102B), one narrow line Seyfert 1 (Ark 564), and one high-luminosity quasar with highly red asymmetric broad line profiles (E1821+643). We found that a significant intrinsic Beff was present in all Type 1 AGNs in our sample. Moreover, we do not see strong difference in intrinsic Beff slopes in different types of AGNs which probably have different physical properties, such as inclination, broad line region geometry, or accretion rate. Additionally, we found that the intrinsic Beff was not connected with the global one, which, instead, could not be detected in the broad H$\alpha$ or H$\beta$ emission lines. In the case of NGC 4151, the detected variation of the Beff slope could be due to the change in the site of line formation in the BLR. Finally, the intrinsic Beff might be caused by the additional optical continuum component that is not part of the ionization continuum.Comment: 12 pages, 8 figures, Accepted for publication in A&

Spectral monitoring of AGNs: Preliminary results for Ark 564 and Arp 102B

We present preliminary results of the long term spectral monitoring of two active galactic nuclei with different broad line shapes: Ark 564 and Arp 102B. Ark 564 is a bright nearby narrow line Syfert 1 (NLS1) galaxy with relatively narrow permitted optical emission lines and a high FeII/H${\beta}$ ratio, while Arp 102B is a nearby broad-line radio galaxy with broad double-peaked Balmer emission lines. The spectra of Ark 564 were observed during 11-year period (1999-2009) and the spectra of Arp 102B in the 12-year period (1998-2009), with SAO 6-m and 1-m telescopes (Russia) and the GHAO 2.1-m telescope (Cananea, Mexico).Comment: Presented on "8th Serbian Conference on Spectral Line Shapes in Astrophysics". In revised version minor changes in the tex

Acousto-optic and opto-acoustic modulation in piezo-optomechanical circuits

Acoustic wave devices provide a promising chip-scale platform for efficiently coupling radio frequency (RF) and optical fields. Here, we use an integrated piezo-optomechanical circuit platform that exploits both the piezoelectric and photoelastic coupling mechanisms to link 2.4 GHz RF waves to 194 THz (1550 nm) optical waves, through coupling to propagating and localized 2.4 GHz acoustic waves. We demonstrate acousto-optic modulation, resonant in both the optical and mechanical domains, in which waveforms encoded on the RF carrier are mapped to the optical field. We also show opto-acoustic modulation, in which the application of optical pulses gates the transmission of propagating acoustic waves. The time-domain characteristics of this system under both pulsed RF and pulsed optical excitation are considered in the context of the different physical pathways involved in driving the acoustic waves, and modeled through the coupled mode equations of cavity optomechanics.Comment: 8 pages, 6 figure