- ID:
- ivo://CDS.VizieR/J/A+A/629/A102
- Title:
- Halpha data cube of Stephan's Quintet
- Short Name:
- J/A+A/629/A102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stephan's Quintet (SQ), the prototypical compact group of galaxies in the local Universe, has been observed with the imaging Fourier transform spectrometer SITELLE, attached to the Canada-France-Hawaii- Telescope, to perform a deep search for intergalactic star-forming emission. In this paper we present the extended ionised gaseous structures detected and analyse their kinematical properties. The large field of view (11'x11') and the spectral ranges of SITELLE have allowed a thorough study of the entire galaxy system, its interaction history and the main properties of the ionised gas. The observations have revealed complex three-dimensional strands in SQ seen for the first time, as well as the spatially resolved velocity field for a new SQ dwarf galaxy (M82-like) and the detailed spectral map of NGC7320c, confirming its AGN nature. A total of 175 SQ Halpha emission regions have been found, 22 of which present line profiles with at least two kinematical components. We studied 12 zones and 28 sub-zones in the SQ system in order to define plausible physical spatial connections between its different parts in the light of the kinematical information gathered. In this respect we have found five velocity systems in SQ: i) v=[5600-5900]km/s associated with the new intruder and the southern debris region; ii) v=[5900-6100]km/s, associated with the north starburst A and south starburst A and the strands connected to these zones; iii) v=[6100-6600]km/s, associated with the strands from the large-scale shock region (LSSR); iv) v=[6600-6800]km/s, associated with the young tidal tail, the starburst A (SQA), NGC7319, and the NGC7319 north lobe; and v) v=[6800-7000]km/s, associated with the strands seen connecting LSSR with SQA. We fail to detect ionised gas emission in the old tail, neither in the vicinity of NGC7318A nor in NGC7317, and the connection between NGC7319 north lobe and SQA cannot be confirmed. Conversely, a clear gaseous bridge has been confirmed both spatially and kinematically between the LSSR zone and the NGC7319 AGN nucleus. Finally, a larger scale, outer rim winding the NGC7318B/A system clockwise north-west to south-east has been highlighted in continuum and in H{alpha}. This structure may be reminiscent of a sequence of a previously proposed scenario for SQ a sequence of individual interactions.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/509/A11
- Title:
- H{alpha} emission-line objects in SMC clusters
- Short Name:
- J/A+A/509/A11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Slitless CCD spectra were obtained covering the bulk (about 3 square degrees) of the Small Magellanic Cloud. For H{alpha} line-emission twice as strong as the ambient continuum, the survey is complete to spectral type B2/B3 on the main sequence. About 8120 spectra of 4437 stars were searched for emission lines in 84 open clusters, and 370 emission-line stars were found, among them at least 231 close to the main sequence. For 176 of them, photometry is available from the OGLE database. For comparison with a higher-metallicity environment, the Galactic sample of the photometric H{alpha} survey by McSwain & Gies (2005, Cat. <J/ApJS/161/118>) was used. Among early spectral sub-types, Be stars are more frequent by a factor ~3-5 in the SMC than in the Galaxy. The distribution with spectral type is similar in both galaxies, i.e., not strongly dependent on metallicity. The fraction of Be stars does not seem to vary with local star density. The Be phenomenon mainly sets in towards the end of the main-sequence evolution (this trend may be more pronounced in the SMC); but some Be stars already form with Be-star characteristics. In small subsamples (such as single clusters), even if they appear identical, the fraction of emission-line stars can deviate drastically from the mean. In all probability, the fractional critical angular rotation rate, OMC, is one of the main parameters governing the occurrence of the Be phenomenon. If the Be character is only acquired during the course of evolution, the key circumstance is the evolution of OMC, which is not only dependent on metallicity but differently so for different mass ranges. As a result, even if the Be phenomenon is driven basically by a single parameter (namely OMC), it can assume a complex multi-parametric appearance. The large cluster-to-cluster differences, which seem stronger than all other variations, serve as a caveat that this big picture may undergo significant second-order modulations (e.g., pulsations, initial angular momentum, etc).
- ID:
- ivo://CDS.VizieR/J/MNRAS/384/1277
- Title:
- H{alpha} emission line sources from IPHAS
- Short Name:
- J/MNRAS/384/1277
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first catalogue of point-source H{alpha} emission line objects selected from the INT/WFC Photometric H{alpha} Survey of the Northern Galactic Plane (IPHAS). In total, our catalogue contains 4853 point sources that exhibit strong photometric evidence for H{alpha} emission. The catalogue is a conservative subset of the emitters present in IPHAS and it is likely that there are many more H{alpha} emitters present in the area of the Galactic Plane that IPHAS observes. Our selection criteria are designed to be conservative (rather than complete) in order to avoid a significant number of false positives in the catalogue. In line with this, we find that of the ~300 catalogue sources for which we have preliminary spectroscopic follow-up observations, more than 95% are confirmed as genuine emission-line sources.
- ID:
- ivo://CDS.VizieR/J/AJ/134/2474
- Title:
- H{alpha} emission-line stars in 7 dwarfs galaxies
- Short Name:
- J/AJ/134/2474
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a search for H{alpha} emission-line stars in M31, M33, and seven dwarfs in or near the Local Group (IC 10, NGC 6822, WLM, Sextans B, Sextans A, Pegasus, and the Phoenix dwarf) using interference filter imaging with the KPNO and CTIO 4m telescopes and Mosaic cameras. The survey is aimed primarily at identifying new luminous blue variables (LBVs) from their spectroscopic similarity to known LBVs, avoiding the bias toward photometric variability, which may require centuries to manifest itself if LBVs go through long quiescent periods. Follow-up spectroscopy with WIYN confirms that our survey detected a wealth of stars whose spectra are similar to the known LBVs.
- ID:
- ivo://CDS.VizieR/J/AJ/143/3
- Title:
- H{alpha} emission stars in IC 1274
- Short Name:
- J/AJ/143/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- IC 1274 is a faintly luminous nebula lying on the near surface of the Lynds 227 (L227) molecular cloud. Its cavity-like morphology is reminiscent of a blistered star-forming region. Four luminous, early-type (B0-B5) stars are located within a spherical volume ~5' in diameter that appears to be clear of heavy obscuration. Approximately centered in the cleared region is the B0 V star HD 166033, which is thought to be largely responsible for the cavity's excavation. Over 80 H{alpha} emission sources brighter than V~21 have been identified in the region. More than half of these are concentrated in IC 1274 and are presumably members of a faint T Tauri star population. Chandra Advanced CCD Imaging Spectrometer imaging of a nearby suspected pulsar and time-variable {gamma}-ray source (GeV J1809-2327) detected 21 X-ray sources in the cluster vicinity, some of which are coincident with the early-type stars and H{alpha} emitters in IC 1274. Deep (V~22) optical BVRI photometry has been obtained for the cluster region. A distance of 1.82+/-0.3kpc and a mean extinction of AV~1.21+/-0.2mag follow from photometry of the early-type stars. Using pre-main-sequence evolutionary models, we derive a median age for the H{alpha} emitters and X-ray sources of ~1Myr; however, a significant dispersion is present. The displaced material was driven against what remains of the molecular cloud to the east, enabling the formation of the substantial number of T Tauri stars found there. A dispersed population of H{alpha} emitters is also found along the periphery of L227, IC 1275, and IC 4684.
- ID:
- ivo://CDS.VizieR/J/AJ/131/1530
- Title:
- H{alpha} emission stars in LDN988
- Short Name:
- J/AJ/131/1530
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- L988 is a large (~0.5{deg}x0.7{deg}) dark cloud complex at about 600pc that contains several bright pre-main-sequence objects (such as V1331 Cyg and LkH{alpha} 321), but this paper deals in detail only with a small region on its eastern edge, near the HAeBe star LkH{alpha} 324. That star and its distant companion LkH{alpha} 324SE lie at the apex of a V-shaped area apparently excavated from the edge of L988, and are the brightest members of a small cluster containing about 50 H{alpha}-emission stars.
- ID:
- ivo://CDS.VizieR/J/AJ/130/1805
- Title:
- H{alpha} emission stars in NGC 2362
- Short Name:
- J/AJ/130/1805
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An H{alpha} emission survey of the young cluster NGC 2362 resulted in the detection of 130 H{alpha} emission stars in an 11'x11' field approximately centered on the fourth magnitude O9 Ib multiple star {tau} CMa. The survey was carried out using the wide-field grism spectrograph on the University of Hawaii 2.2m telescope and the Gemini Multi-Object Spectrograph (GMOS) on Gemini North. Deep optical VR_C_I_C_ (to V~23.0) and near-infrared (NIR) photometry (JHK) to K~16 were obtained for several fields within the cluster. Spectra covering the 6000-8000{AA} region at a resolution of R~3000 (adequate for the determination of LiI{lambda}6708 line strengths) were also acquired for ~200 pre-main-sequence (PMS) candidates with GMOS.
- ID:
- ivo://CDS.VizieR/J/AJ/129/829
- Title:
- H{alpha} emission stars in NGC 2264
- Short Name:
- J/AJ/129/829
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An H{alpha} emission survey of the young cluster NGC 2264 in the Mon OB1 association resulted in the detection of 490 H{alpha} emission stars in a 25'x40' field approximately centered between the O7 V multiple star S Mon and the Cone Nebula. The survey was carried out with the wide-field grism spectrograph (WFGS) on the University of Hawaii 2.2m telescope on Mauna Kea. X-ray observations made with the European Photon Imaging Camera (EPIC) on board the European Space Agency's XMM-Newton satellite observatory will be discussed in a subsequent paper. Optical (BVR_C_I_C_) photometry was obtained for selected fields to supplement similar data from the literature. Spectra covering the 6000-8000{AA} region at a resolution of R~3000 (adequate for the determination of Li I {lambda}6708 line strengths) were obtained for 150 H{alpha} and X-ray emission sources with the Gemini Multi-Object Spectrograph (GMOS).
- ID:
- ivo://CDS.VizieR/II/309
- Title:
- H{alpha} emission stars in the Orion Nebula
- Short Name:
- II/309
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog of 534 H{alpha} emission lines stars in the region of the Orion Nebula (5{deg}x5{deg}) is presented, an the basis of 240 "new" H{alpha} stars found on Tonantzintla spectral plates and previous known H{alpha} emission stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/416/2041
- Title:
- H{alpha} emitters at z=2.23
- Short Name:
- J/MNRAS/416/2041
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a narrow-band (H_2_S1, {lambda}_c_=2.121um, {delta}{lambda}=0.021um) imaging search with Wide Field Camera/United Kingdom Infrared Telescope for H{alpha} emitters (HAEs) around several potential signposts of rare (~10^-7^-10^-8^ comoving Mpc^-3^) overdense regions at z=2.23: an overdensity of quasi-stellar objects [QSOs; 2dF QSO Redshift Survey (2QZ) cluster], a powerful, high-redshift radio galaxy (HzRG) and a concentration of submillimetre galaxies (SMGs) and optically faint radio galaxies (OFRGs). In total, we detect 137 narrow-band emitter candidates down to emission-line fluxes of 0.5-1x10^-16^erg/s/cm^2^, across a total area of 0.56deg^2^ (2.1x10^5^ comoving Mpc^3^ at z=2.23) in these fields.
