We have found three new LBV candidates in the star-forming galaxy NGC 4736. They show typical well-known LBV spectra, broad and strong hydrogen lines, He i lines, many Fe ii lines, and forbidden [Fe ii] and [Fe iii]. Using archival Hubble Space Telescope and ground-based telescope data, we have estimated the bolometric magnitudes of these objects from -8.4 to -11.5, temperatures, and reddening. Source NGC 4736 1 (M V = −10.2 ± 0.1 mag) demonstrated variability between 2005 and 2018 as ∆V ≈ 1.1 mag and ∆B ≈ 0.82 mag, the object belongs to LBV stars. NGC 4736 2 (M V < −8.6 mag) shows P Cyg profiles and its spectrum has changed from 2015 to 2018. The brightness variability of NGC 4736 2 is ∆V ≈ 0.5 mag and ∆B ≈ 0.4 mag. In NGC 4736 3 (M V = −8.2 ± 0.2 mag), we found strong nebular lines, broad wings of hydrogen; the brightness variation is only ≈ 0.2 mag. Therefore, the last two objects may reside to LBV candidates.
We present the results of our identification of eight objects from a preliminary catalogue of X-ray sources detected in the 4-12 keV energy band by the Mikhail Pavlinsky ART-XC telescope aboard the SRG observatory during its first all-sky survey. Three of them (SRGA J005751.0 + 210846, SRGA J014157.0 − 032915, SRGA J232446.8 + 440756) have been discovered by ART-XC, while five were already known previously as X-ray sources, but their nature remained unknown. The last five sources have also been detected in soft X-rays by the eROSITA telescope of the SRG observatory. Our optical observations were carried out at the 1.6-m AZT-33IK telescope of the Sayan Observatory and the 1.5-m Russian-Turkish telescope (RTT-150). All of the investigated objects have turned out to be active galactic nuclei (AGNs) at redshifts from 0.019 to 0.283. Six of them are Seyfert 2 galaxies (including one Seyfert 1.9 galaxy), one (SRGA J005751.0+210846) is a "hidden" AGN (in an edge-on galaxy), and one (SRGA J224125.9 + 760343) is a narrow-line Seyfert 1 galaxy. The latter object is characterized by a high X-ray luminosity (∼ (2 − 13) × 10 44 erg s −1 in the 4-12 keV band) and, according to our black hole mass estimate (∼ 2 × 10 7 M ), an accretion rate close to the Eddington limit. All three AGNs discovered by the ART-XC telescope (which are not detected by the eROSITA telescope) are characterized by a high absorption column density (N H 3 × 10 23 cm −2 ). The results obtained confirm the expectations that the ART-XC telescope is an efficient instrument for searches of heavily obscured and other interesting AGNs in the nearby (z 0.3) Universe. The SRG all-sky survey will last for more than 3 years more, which will allow many such objects to be discovered.
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