Emergence of a Narrow H<sub>2</sub>O Maser Feature in NGC 1052

Kameno, Seiji; Nakai, Naomasa; Sawada-Satoh, Satoko; Sato, Naoko; Haba, A.

doi:10.1086/426936

Cited by 27 publications

(38 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Significant H 2 O maser emission within the velocity range of 1550-1850 km s −1 were detected, 50-350 km s −1 redshifted from the systemic velocity of the galaxy, and it is consistent with past single-dish observations (Braatz et al 1994(Braatz et al , 1996Braatz et al 2003;Kameno et al 2005). The maser spots consist of two clusters; the eastern cluster and the western cluster are located on knots B and C3, respectively.…”

Section: H 2 O Maser Emissionsupporting

confidence: 89%

See 1 more Smart Citation

H₂O maser and a plasma obscuring torus in the radio galaxy NGC 1052

Sawada-Satoh¹,

Kameno

Nakamura

et al. 2009

Astron Nachr

View full text Add to dashboard Cite

We present multi-frequency simultaneous VLBA observations at 15, 22 and 43 GHz towards the nucleus of the nearby radio galaxy NGC 1052. These three continuum images reveal a double-sided jet structure, whose relative intensity ratios imply that the jet axis is oriented close to the sky plane. The steeply rising spectra at 15-43 GHz at the inner edges of the jets strongly suggest that synchrotron emission is absorbed by foreground thermal plasma. We detected H2O maser emission in the velocity range of 1550-1850 km s −1 , which is redshifted by 50-350 km s −1 with respect to the systemic velocity of NGC 1052. The redshifted maser gas appears projected against both sides of the jet, similar to the H I seen in absorption. The H2O maser gas is located where the free-free absorption opacity is large. This probably implies that the masers in NGC 1052 are associated with a circumnuclear torus or disk as in the nucleus of NGC 4258. Such circumnuclear structure can be the sense of accreting onto the central engine.

show abstract

Section: H 2 O Maser Emissionsupporting

confidence: 89%

“…Excitation by shocks into the dense molecular clump which lies in or around the radio jet, or amplification of the radio continuum emission of the jet by foreground molecular clouds, were suggested by Claussen et al (1998). On the other hand, Kameno et al (2005) …”

Section: Introductionmentioning

confidence: 98%

H₂O maser and a plasma obscuring torus in the radio galaxy NGC 1052

Sawada-Satoh¹,

Kameno

Nakamura

et al. 2009

Astron Nachr

View full text Add to dashboard Cite

show abstract

“…Here we take T ex = 100 K and 230 K, as recent millimeter and submillimeter interferometric observations have detected the vibrationally excited HCN emission lines in the dust-enshrouded AGN of the luminous infrared galaxies (Sakamoto et al 2010;Imanishi & Nakanishi 2013 23 cm −2 from modeling of Xray spectra (Guainazzi & Antonelli 1999;Weaver et al 1999;Guainazzi et al 2000;Brenneman et al 2009), and the electron column density of ∼ 10 23 cm −2 estimated from the FFA opacity of the dense plasma (Sawada-Satoh et al 2009). Kameno et al (2005) and Sawada-Satoh et al (2008) proposed that the circumnuclear torus consists of several phase layers. On the inner surface of the torus, a hot (∼ 8000 K) plasma layer is formed by X-ray emission from the central engine and it causes FFA.…”

Section: Absorbing Molecular Gas Propertiesmentioning

confidence: 99%

“…An H 2 O megamaser emission is detected at velocities by redshifted 50-350 km s −1 with respect to V sys (Braatz et al 1994(Braatz et al , 2003Kameno et al 2005), and the H 2 O maser gas lies on the inner components in the center of NGC 1052, where the plasma torus is obscured (Claussen et al 1998;Sawada-Satoh et al 2008). Neutral atomic hydrogen (H I), OH, HCO + , HCN, CO tran-sitions are found toward the center of NGC 1052 as absorptions (van Gorkom et al 1986;Omar et al 2002;Liszt & Lucas 2004;Impellizzeri et al 2008).…”

Section: Introductionmentioning

confidence: 96%

Spatially Resolved HCN Absorption Features in the Circumnuclear Region of NGC 1052

Sawada-Satoh

Roh

et al. 2016

ApJL

Self Cite

View full text Add to dashboard Cite

We present the first VLBI detection of HCN molecular absorption in the nearby active galactic nucleus NGC 1052. Utilizing the 1 mas resolution achieved by the Korean VLBI Network, we have spatially resolved the HCN absorption against a double-sided nuclear jet structure. Two velocity features of HCN absorption are detected significantly at the radial velocity of 1656 and 1719 km s −1 , redshifted by 149 and 212 km s −1 with respect to the systemic velocity of the galaxy. The column density of the HCN molecule is estimated to be 10 15 -10 16 cm −2 , assuming an excitation temperature of 100-230 K. The absorption features show high optical depth localized on the receding jet side, where the free-free absorption occurred due to the circumnuclear torus. The size of the foreground absorbing molecular gas is estimated to be on approximately one-parsec scales, which agrees well with the approximate size of the circumnuclear torus. HCN absorbing gas is likely to be several clumps smaller than 0.1 pc inside the circumnuclear torus. The redshifted velocities of the HCN absorption features imply that HCN absorbing gas traces ongoing infall motion inside the circumnuclear torus onto the central engine.

show abstract

“…Follow-up VLBI observations of Mrk 348 indicated the H 2 O maser emission distributed along with a jet component in the galaxy (Peck et al 2003). In the elliptical galaxy NGC 1052 which is classified as a LINER (Ho et al 1997), Kameno et al (2005) revealed the correlation between H 2 O maser flux and radio continuum flux on a timescale of days, which is possibly due to an interaction of a sub-relativistic jet and a combination of ionized and X-ray dissociated regions. Considering these facts, one might be able to predict the timing of the maser flare in NGC 6240 by monitoring the continuum flux at short time intervals.…”

Section: Nuclear Maser In Agnmentioning

confidence: 99%

Two Epochs of Very Large Array Observations of Water Maser Emission in the Active Galaxy NGC 6240

Hagiwara

2010

The Astronomical Journal

View full text Add to dashboard Cite

Studies of 22 GHz H 2 O maser emission from the merging galaxy NGC 6240 with double nuclei are presented. Two epochs of Very Large Array (VLA) observations in the A-configuration in spectral-line mode were carried out at 0.1 arcsec resolution by covering the redshifted velocity range of ∼300 km s −1 with respect to the systemic velocity of the galaxy. The purpose of these new observations is twofold: to detect an H 2 O maser that an earlier VLA observation pinpointed in the southern nucleus in the northern nucleus as well to clarify the kinematics of the double nuclei, and to understand the origin of the maser in the galaxy. In the second epoch, one velocity feature peaking at V LSR = 7491.1 km s −1 , redshifted by ∼200 km s −1 relative to the systemic velocity, was detected only toward the southern nucleus. The detection of an H 2 O maser feature at or near this velocity had never been reported in earlier observations. However, including the known velocity features at redshifted velocities, no other velocity features were observed toward either nuclei throughout these epochs. The maser remains unresolved at an angular resolution of ∼0. 1, corresponding to a linear size of less than about 45 pc. The two epochs of VLA observations show that the maser intensity is variable on timescales of at least three months, while the correlation between the maser intensity and the radio continuum intensity is not certain from our data. It is plausible that the maser in NGC 6240 is associated with the activity of an active galactic nucleus in the southern nucleus. Alternatively, the maser can be explained by star-forming activity at the site of massive star formation in the galaxy.

show abstract

Emergence of a Narrow H₂O Maser Feature in NGC 1052

Cited by 27 publications

References 24 publications

H₂O maser and a plasma obscuring torus in the radio galaxy NGC 1052

H₂O maser and a plasma obscuring torus in the radio galaxy NGC 1052

Spatially Resolved HCN Absorption Features in the Circumnuclear Region of NGC 1052

Two Epochs of Very Large Array Observations of Water Maser Emission in the Active Galaxy NGC 6240

Contact Info

Product

Resources

About

Emergence of a Narrow H2O Maser Feature in NGC 1052

Cited by 27 publications

References 24 publications

H2O maser and a plasma obscuring torus in the radio galaxy NGC 1052

H2O maser and a plasma obscuring torus in the radio galaxy NGC 1052

Spatially Resolved HCN Absorption Features in the Circumnuclear Region of NGC 1052

Two Epochs of Very Large Array Observations of Water Maser Emission in the Active Galaxy NGC 6240

Contact Info

Product

Resources

About

Emergence of a Narrow H₂O Maser Feature in NGC 1052

H₂O maser and a plasma obscuring torus in the radio galaxy NGC 1052

H₂O maser and a plasma obscuring torus in the radio galaxy NGC 1052