- ID:
- ivo://CDS.VizieR/J/AJ/116/102
- Title:
- NGC 5548 BR photometry
- Short Name:
- J/AJ/116/102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Deep Hubble Space Telescope Wide Field Camera (WFC-1) imaging of a region 3.7' east of the V=13mag Seyfert galaxy NGC 5548 in the F555W and F785LP bands, and deep ground-based V and I imaging, show a new extended, blue, low surface brightness structure, apparently a remnant of a tidal interaction associated with NGC 5548. If this straight, low surface brightness (V~27-28mag/arcsec^2^) tidal tail is associated with NGC 5548, it extends at least 80kpc from it and has an absolute magnitude of M_V~-16.4 (H_0_=65km/s/Mpc). Previous imaging surveys of Seyfert galaxies would have missed such low surface brightness tails. Morphologically similar to some brighter tails seen in other interacting systems and in simulations of merging galaxies, this faint tail is a useful diagnostic of an earlier interaction and of the progenitors' halo-to-disk mass ratios. Luminous ripples and a brighter tail wrapped around the galaxy are seen in the inner 1-10kpc region. Unresolved blue objects in the long tail have the colors and absolute magnitudes of young globular clusters. Taken together, the two tails and other features suggest that two spirals merged less than ~1Gyr ago. The inner luminosity profile of NGC 5548 is a good fit to a de Vaucouleurs profile with r_eff_=5.8kpc. Recent simulations of merged galaxies with high-mass halos fail to form lasting tidal tails, suggesting that the NGC 5548 progenitor spirals had modest halo masses.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/632/A61
- Title:
- NGC1068 CO and HCO images
- Short Name:
- J/A+A/632/A61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the fueling and the feedback of nuclear activity in the Seyfert 2 galaxy NGC1068, by studying the distribution and kinematics of molecular gas in the torus and its connections. We use ALMA to image the emission of a set of molecular gas tracers in the circumnuclear disk (CND) and the torus of the galaxy using the CO(2-1), CO(3-2) and HCO^+^(4-3) lines with spatial resolutions ~0.03"-0.09"(2-6pc). ALMA resolves the CND as an asymmetric ringed disk of D~400pc-size and mass of ~1.4x10^8^M_{sun}_. The inner edge of the ring is associated with edge-brightened arcs of NIR polarized emission identified with the working surface of the AGN ionized wind. ALMA proves the existence of a molecular torus of M_torus ~3x10^5^M_{sun}_, which extends over a large range of spatial scales D=10-30pc around the central engine. The new observations evidence the density radial stratification of the torus: the HCO^+^(4-3) torus, with a full size D=11pc, is a factor of 2-3 smaller than its CO(2-1) and CO(3-2) counterparts, which have full-sizes D=26pc and D=28pc, respectively. The torus is connected to the CND through a network of gas streamers. The kinematics of molecular gas show strong departures from circular motions in the torus, the gas streamers, and the CND. These velocity distortions are interconnected and are part of a 3D outflow that reflects the effects of AGN feedback on the kinematics of molecular gas across a wide range of spatial scales. We conclude that a wide-angle AGN wind launched from the accretion disk is impacting a sizeable fraction of the gas inside the torus (~0.4-0.6xM_torus_). However, a large gas reservoir (~1.2-1.8x10^5^M_{sun}_) close to the equatorial plane of the torus remains unaffected by the AGN wind and can continue fueling the AGN for ~1-4Myr. AGN fueling seems nevertheless thwarted on intermediate scales (15pc<r<50pc).
- ID:
- ivo://CDS.VizieR/J/A+A/320/405
- Title:
- NGC 5548 continuum light curve
- Short Name:
- J/A+A/320/405
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The variations of the [OIII]{lambda}5007 line profile in NGC 5548 are examine d from CCD spectra obtained at the Ohio State University and Crimean Astrophysic al Observatory in December 1988 - October 1994.
- ID:
- ivo://CDS.VizieR/J/A+A/634/A1
- Title:
- NGC 1068 GRAVITY reconstructed image
- Short Name:
- J/A+A/634/A1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-infrared interferometric data on the Seyfert 2 galaxy NGC 1068, obtained with the GRAVITY instrument on the European Southern Observatory Very Large Telescope Interferometer. The extensive baseline coverage from 5 to 60M{lambda} allowed us to reconstruct a continuum image of the nucleus with an unrivaled 0.2pc resolution in the K-band.We find a thin ring-like structure of emission with a radius r=0.24+/-0.03pc, inclination i=70+/-5{deg}, position angle PA=-50+/-4{deg}, and h/r<0.14, which we associate with the dust sublimation region. The observed morphology is inconsistent with the expected signatures of a geometrically and optically thick torus. Instead, the infrared emission shows a striking resemblance to the 22GHz maser disc, which suggests they share a common region of origin. The near-infrared spectral energy distribution indicates a bolometric luminosity of (0.4-4.7)x10^45^erg/s, behind a large A_K_~=5.5 (A_V_~=90) screen of extinction that also appears to contribute significantly to obscuring the broad line region.
- ID:
- ivo://CDS.VizieR/J/A+A/558/A87
- Title:
- NGC6240 high resolution mapping of CO(1-0)
- Short Name:
- J/A+A/558/A87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present long baseline CO(1-0) mapping of the luminous infrared galaxy NGC 6240 obtained with the IRAM - Plateau de Bure Interferometer. This source is a well known early-stage merging system hosting two active galactic nuclei (AGN). We find a broad CO(1-0) line profile with maximum velocity 800km/s and a total line width of 1400km/s that displays several kinematic components, revealing the complexity of the gas dynamics in this system. We detect a blueshifted CO emission with velocity between -200 and -500 km/s, which peaks around the southern AGN at the same position where the H_2_ outflow is located. We interpret this blueshifted component as an outflow with a mass loss rate of ~500M_{sun}_/yr, originating from the southern nucleus.
- ID:
- ivo://CDS.VizieR/J/A+A/551/A81
- Title:
- NGC 6951 intensity and velocity maps
- Short Name:
- J/A+A/551/A81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Gas inflowing along stellar bars is often stalled at the location of circumnuclear rings, which form an effective reservoir for massive star formation and thus shape the central regions of galaxies. However, how exactly star formation proceeds within these circumnuclear starburst rings is the subject of debate. Two main scenarios for this process have been put forward. In the first, the onset of star formation is regulated by the total amount of gas present in the ring with star forming starting, once a mass threshold has been reached, in "random" positions within the ring like "popcorn". In the second, star formation primarily takes place near the locations where the gas enters the ring. This scenario has been dubbed "pearls-on-a-string". Here we combine new optical IFU data covering the full stellar bar with existing multiwavelength data to study the 580pc radius circumnuclear starburst ring in detail in the nearby spiral galaxy NGC 6951. Using Hubble Space Telescope (HST) archival data together with SAURON and OASIS IFU data, we derive the ages and stellar masses of star clusters, as well as the total stellar content of the central region.
- ID:
- ivo://CDS.VizieR/J/A+AS/131/105
- Title:
- NGC 6221 ionized gas kinematics
- Short Name:
- J/A+AS/131/105
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Rotation curves and velocity dispersion profiles are presented for both the stellar and gaseous components along five different position angles (PA =5{deg}, 50{deg}, 95{deg}, 125{deg}, and 155{deg}) of the nearby barred spiral NGC 6221. The observed kinematics extends out to about 80'' from the nucleus. Narrow and broad-band imaging is also presented. The radial profiles of the fluxes ratio [NII] ({lambda} 6583.4{AA})/H{alpha} reveal the presence of a ring-like structure of ionized gas, with a radius of about 9'' and a deprojected circular velocity of about 280km/s. The analysis of the dynamics of the bar indicates this ring is related to the presence of an inner Lindblad resonance (ILR) at 1.3kpc. NGC 6221 is found to exhibit intermediate properties between those of the early-type barred galaxies: the presence of a gaseous ring at an ILR, the bar edge located between the ILR's and the corotation radius beyond the steep rising portion of the rotation curve, the dust-lane pattern, and those of the late-type galaxies: an almost exponential surface brightness profile, the presence of H{alpha} regions along all the bar, the spiral-arm pattern. It is consistent with scenarios of bar-induced evolution from later to earlier-type galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/632/799
- Title:
- NGC4395 light curves
- Short Name:
- J/ApJ/632/799
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A reverberation-mapping program on NGC 4395, the least luminous known Seyfert 1 galaxy, undertaken with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope yields a measurement of the mass of the central black hole M_BH_=(3.6+/-1.1)x10^5^M_{sun}_. The observations consist of two visits of five orbits each, in 2004 April and July. During each of these visits, the UV continuum varied by at least 10% (rms), and only C IV {lambda}1549 showed corresponding variations large enough to reliably determine the emission-line lag, which was measured to be of order 1-hr for both visits.
- ID:
- ivo://CDS.VizieR/J/ApJ/650/88
- Title:
- NGC4395 light curves. III.
- Short Name:
- J/ApJ/650/88
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical observations of the low-luminosity Seyfert 1 nucleus of NGC 4395, as part of a multiwavelength reverberation-mapping program. Observations were carried out over two nights in 2004 April at Lick, Wise, and Kitt Peak Observatories. We obtained V- and B-band photometry, and spectra over the range 3500-6800{AA}. Simultaneous Hubble Space Telescope UV and Chandra X-ray observations are presented in companion papers.
- ID:
- ivo://CDS.VizieR/J/A+A/324/904
- Title:
- NGC 4151 line-continuum diagram sequences
- Short Name:
- J/A+A/324/904
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results of an 8-year spectroscopic monitoring of the Seyfert 1.5 galaxy NGC 4151 carried out with a CCD spectrograph at the 2.6-m Shajn Telescope of the Crimean Astrophysical Observatory in 1988-1995. Total of 202 H{ alpha} region spectra and 154 H{beta} region spectra have formed the data set. A ll spectra were calibrated in flux using the narrow emission lines which were as summed to be constant over the duration of the monitoring program.
