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- 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.
2513. NGC 5523 H-band image
- ID:
- ivo://CDS.VizieR/J/A+A/598/A119
- Title:
- NGC 5523 H-band image
- Short Name:
- J/A+A/598/A119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Multi-band images of the very isolated spiral galaxy NGC 5523 show a number of unusual features consistent with NGC 5523 having experienced a significant merger: (1) Near-infrared (NIR) images from the Spitzer Space Telescope (SST) and the WIYN 3.5-m Multi-band images of the very isolated spiral galaxy NGC 5523 show a number of unusual features consistent with NGC 5523 having experienced a significant merger: (1) Near-infrared (NIR) images from the Spitzer Space Telescope (SST) and the WIYN 3.5-m telescope reveal a nucleated bulge-like structure embedded in a spiral disk. (2) The bulge is offset by ~1.8kpc from a brightness minimum at the center of the optically bright inner disk. (3) A tidal stream, possibly associated with an ongoing satellite interaction, extends from the nucleated bulge along the disk. We interpret these properties as the results of one or more non-disruptive mergers between NGC 5523 and companion galaxies or satellites, raising the possibility that some galaxies become isolated because they have merged with former companions.
- ID:
- ivo://CDS.VizieR/J/A+A/575/A17
- Title:
- NGC 891 Herschel PACS and SPIRE spectroscopy
- Short Name:
- J/A+A/575/A17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Herschel PACS and SPIRE spectroscopy of the most important far- infrared cooling lines in the nearby edge-on spiral galaxy, NGC 891: the [CII] 158, [NII] 122, 205, [OI] 63, 145, and [OIII] 88 micron lines. We find that the photoelectric heating efficiency of the gas varies from a mean of 3.5x10^-3^ in the centre up to 8x10^-3^ at increasing radial and vertical distances in the disc. We compare the observed flux of the FIR cooling lines and total IR emission with the predicted flux from a PDR model to determine the gas density, surface temperature and the strength of the incident far-ultraviolet (FUV) radiation field, G_0_. Resolving details on physical scales of ~0.6kpc, a pixel-by-pixel analysis reveals that the majority of the PDRs in NGC 891's disc have hydrogen densities of 1<log(n/cm^-3^)<3.5 experiencing an incident FUV radiation field with strengths of 1.7<logG_0_<3. Although these values we derive for most of the disc are consistent with the gas properties found in PDRs in the spiral arms and inter-arm regions of M51, observed radial trends in n and G_0_ appear to be sensitive to varying optical thickness in the lines, demonstrating the importance of accurately accounting for optical depth effects when interpreting observations of high inclination systems. With an empirical relationship between the MIPS 24 micron and [NII] 205 micron emission, we estimate an enhancement of the FUV radiation field strength in the far north-eastern side of the disc.
- 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.
2516. NGC 628 H II regions
- ID:
- ivo://CDS.VizieR/J/AJ/120/1306
- Title:
- NGC 628 H II regions
- Short Name:
- J/AJ/120/1306
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Employing deep H{alpha} narrowband imagery, we identified and measured the fluxes of 137 small H II regions in the extreme outer disk (R>=R_25_) of the nearly face-on, Sc I galaxy NGC 628. A majority of these H II regions are located in two faint, outer spiral arms visible in H I maps. The faintest H II regions that could be measured have fluxes of only a few times 10^-16^ergs/cm^2^/s, which correspond to luminosities of 10^36^ergs/s, or a fraction of the Orion Nebula luminosity. The most distant object detected is at R~27kpc from the galaxy center. The massive star formation rate, as measured from the azimuthally averaged H{alpha} flux, is consistent with a monotonic decrease as far as R~1.3R_25_ (20kpc), where there is a sharp drop. The Schmidt law for the whole disk of NGC 628 corresponds to a relatively steep power law with n=2.9+/-0.2, but it "fails" below {Sigma}gas<=4M_{sun}_/pc^2^; the index depends strongly on the CO data used. We derived the luminosity function (LF) of 598 H II regions over the whole disk, and we compared the shapes of the cumulative LFs between R>=R_25_ and R<R_25_; the LF of the outer regions is significantly steeper than that of the inner regions.
- 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.
2519. NGC4395 light curves
- 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.
