- ID:
- ivo://CDS.VizieR/J/A+A/445/79
- Title:
- Nearby early-type gal. with ionized gas. II.
- Short Name:
- J/A+A/445/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Rampazzo et al., 2005, Cat. <J/A+A/433/497> (Paper I) presented a data-set of line-strength indices for 50 early-type galaxies in the nearby Universe. The galaxy sample is biased toward galaxies showing emission lines, located in environments corresponding to a broad range of local galaxy densities, although predominantly in low density environments. The present addendum enlarges the above data-set of line-strength indices by analyzing 18 additional early-type galaxies (three galaxies, NGC 3607, NGC 5077 and NGC 5898 were presented in the previous set). We measured 25 line-strength indices, defined by the Lick IDS "standard" system (Trager et al., 1998, Cat. <J/ApJS/116/1>; Worthey & Ottaviani, 1997, Cat. <J/ApJS/111/377>), for 7 luminosity weighted apertures and 4 gradients of each galaxy. This addendum presents the line-strength data-set and compares it with the available data in the literature.
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- ID:
- ivo://CDS.VizieR/J/A+A/585/A12
- Title:
- Nearby early-type stars spectroscopic survey
- Short Name:
- J/A+A/585/A12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a high signal-to-noise spectroscopic survey of 670 nearby early-type stars, to map Diffuse Interstellar Band (DIB) absorption in and around the Local Bubble. The project started with a Southern hemisphere survey conducted at the European Southern Observatory's New Technology Telescope and has since been extended to an all-sky survey using the Isaac Newton Telescope. In this first paper in the series, we introduce the overall project and present the results from the Southern hemisphere survey. We make available a catalogue of equivalent-width measurements of the DIBs at 5780, 5797, 5850, 6196, 6203, 6270, 6283 & 6614{AA}, the interstellar NaI D lines at 5890 & 5896{AA}, and the stellar HeI line at 5876{AA}. We find that the 5780{AA} DIB is relatively strong throughout, as compared to the 5797{AA} DIB, but especially within the Local Bubble and at the interface with more neutral medium. The 6203{AA} DIB shows a similar behaviour, but with respect to the 6196{AA} DIB. Some nearby stars show surprisingly strong DIBs whereas some distant stars show very weak DIBs, indicating small-scale structure within as well as outside the Local Bubble. The sight-lines with non-detections trace the extent of the Local Bubble especially clearly, and show it opening out into the Halo. The Local Bubble has a wall which is in contact with hot gas and/or a harsh interstellar radiation field. That wall is perforated though, causing leakage of radiation and possibly hot gas. On the other hand, compact self-shielded cloudlets are present much closer to the Sun, probably within the Local Bubble itself. As for the carriers of the DIBs, our observations confirm the notion that these are large molecules, whose differences in behaviour are mainly governed by their differing resilience and/or electrical charge, with more subtle differences possibly related to varying excitation.
- ID:
- ivo://CDS.VizieR/J/A+A/520/A79
- Title:
- Nearby FGK stars chromospheric activity
- Short Name:
- J/A+A/520/A79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Chromospheric activity produces both photometric and spectroscopic variations that can be mistaken as planets. Large spots crossing the stellar disc can produce planet-like periodic variations in the light curve of a star. Moreover, spots clearly affect the spectral line profiles. Such perturbations will in turn affect the line centroids creating a radial velocity jitter that might "contaminate" the variations induced by a planet. Precise chromospheric activity measurements are needed to estimate the activity-induced noise that should be expected for a given star. The purpose of this paper is to obtain precise chromospheric activity measurements and projected rotational velocities for nearby (d<25pc) cool (spectral types F to K) stars, in order to estimate the activity-related jitter that should be expected for them. As a complementary objective, in this paper we aim to obtain relationships between fluxes in different activity indicator lines, which will permit a transformation of traditional activity indicators, i.e, CaII H & K lines, to other which hold noteworthy advantages. We used high resolution (~50000) echelle optical spectra. Standard data reduction was performed using the IRAF echelle package. To reveal the chromospheric emission of the stars in the sample we used the spectral subtraction technique. We measured equivalent widths of the chromospheric emission lines in the subtracted spectrum and transformed them into fluxes by applying empirical equivalent width-flux relationships. Rotational velocities were determined using the cross-correlation technique. To infer activity-related radial velocity (RV) jitter we used empirical relationships between this and the R'HK index. We have measured chromospheric activity, as given by different indicators throughout the optical spectra, and projected rotational velocities for 371 nearby cool stars. We have built empirical relationships among the most important chromospheric emission lines. Finally, we have used the measured chromospheric activity to estimate the expected RV jitter for the active stars in the sample.
- ID:
- ivo://CDS.VizieR/J/AJ/158/129
- Title:
- Near-infrared hydrogen & helium QSO emission lines
- Short Name:
- J/AJ/158/129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 14 near-infrared (NIR) quasar spectra observed with the Flamingos-2 NIR spectrometer instrument at the Gemini South Observatory. The targets were selected with redshifts of (0.58~<z~<0.63) to ensure the spectral wavelength range included specifically identified hydrogen and helium broad emission lines. We present measurements of their FWHM, equivalent widths, and flux ratios relative to H{alpha}. The quasars are all within the Sloan Digital Sky Survey (SDSS) Stripe 82 region which, then also provides multi-epoch rest-frame UV and optical spectroscopic observations of our targets. In future work, these data and those from Galaxy Evolution Explorer and NUV spectra will be utilized to constrain photoionization models to determine physical conditions within the broad emission line regions, such as the incident ionizing photon flux and gas density.
- ID:
- ivo://CDS.VizieR/J/A+A/452/245
- Title:
- Near-IR photometry of PMS stars in rho Oph
- Short Name:
- J/A+A/452/245
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The aim of this paper is to provide a measurement of the mass accretion rate in a large, complete sample of objects in the core of the star forming region rho Oph. The sample includes most of the objects (104 out of 111) with evidence of a circumstellar disk from mid-infrared photometry; it covers a stellar mass range from about 0.03 to 3M_{sun}_ and it is complete to a limiting mass of ~0.05M_{sun}_. We used J and K-band spectra to derive the mass accretion rate of each object from the intensity of the hydrogen recombination lines, Pa{beta} or Br{gamma}. For comparison, we also obtained similar spectra of 35 diskless objects.
- ID:
- ivo://CDS.VizieR/J/A+A/479/131
- Title:
- Near-IR spectra of inner red giants
- Short Name:
- J/A+A/479/131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The existence in the Milky Way of either a long thin bar with a half length of 4.5kpc and a position angle of around 45{deg} with respect to the Sun-Galactic centre line or a bulge+bar complex, thicker and shorter, with a smaller tilt respect to the Sun-GC line, has been a matter of discussion in recent decades. In this paper, we present low resolution (R=500) near-infrared spectra for selected and serendipitous sources in six inner in-plane Galactic fields at l=7{deg}, 12{deg}, 15{deg}, 20{deg}, 26{deg} and 27{deg}, with the aim of analysing the stellar content present in those fields.
- ID:
- ivo://CDS.VizieR/J/AJ/140/1214
- Title:
- Near-IR spectroscopic survey of class I YSOs
- Short Name:
- J/AJ/140/1214
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a near-IR spectroscopic survey of 110 Class I protostars observed from 0.80um to 2.43um at a spectroscopic resolution of R=1200. This survey is unique in its selection of targets from the whole sky, its sample size, wavelength coverage, depth, and sample selection.
- ID:
- ivo://CDS.VizieR/J/AJ/144/99
- Title:
- Near-IR spectroscopy of 36 late M dwarfs
- Short Name:
- J/AJ/144/99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observations of 36 late M dwarfs obtained with the KeckII/NIRSPEC in the J band at a resolution of ~20000. We have measured projected rotational velocities, absolute radial velocities, and pseudo-equivalent widths of atomic lines. Twelve of our targets did not have previous measurements in the literature. For the other 24 targets, we confirm previously reported measurements. We find that 13 stars from our sample have vsini below our measurement threshold (12km/s) whereas four of our targets are fast rotators (vsini>30km/s). As fast rotation causes spectral features to be washed out, stars with low projected rotational velocities are sought for radial velocity surveys. At our intermediate spectral resolution, we have confirmed the identification of neutral atomic lines reported in McLean et al. We also calculated pseudo-equivalent widths of 12 atomic lines. Our results confirm that the pseudo-equivalent width of KI lines is strongly dependent on spectral types. We observe that the pseudo-equivalent width of FeI and MnI lines remains fairly constant with later spectral type. We suggest that these lines are particularly suitable for deriving metallicities for late M dwarfs.
- ID:
- ivo://CDS.VizieR/J/A+A/551/A93
- Title:
- Nebular emission from z=~2-3 star-forming galaxies
- Short Name:
- J/A+A/551/A93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To investigate the ingredients, which allow star-forming galaxies to present Ly{alpha} line in emission, we studied the kinematics and gas phase metallicity of the interstellar medium. We used multi-object near-infrared spectroscopy with Magellan/MMIRS to study nebular emission from z=~2-3 star-forming galaxies discovered in three MUSYC fields.
- ID:
- ivo://CDS.VizieR/J/MNRAS/421/3325
- Title:
- 2 new candidate luminous blue variables
- Short Name:
- J/MNRAS/421/3325
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of two new Galactic candidate luminous blue variable (LBV) stars via detection of circular shells (typical of confirmed and candidate LBVs) and follow-up spectroscopy of their central stars. The shells were detected at 22um in the archival data of the Mid-Infrared All Sky Survey carried out with the Wide-field Infrared Survey Explorer (WISE). Follow-up optical spectroscopy of the central stars of the shells conducted with the renewed Southern African Large Telescope (SALT) showed that their spectra are very similar to those of the well-known LBVs P Cygni and AG Car, and the recently discovered candidate LBV MN112, which implies the LBV classification for these stars as well.
