- ID:
- ivo://CDS.VizieR/I/335
- Title:
- LUT Survey Catalogue Data Release 1
- Short Name:
- I/335
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an near-ultraviolet star catalogue extracted from the Lunar-based Ultraviolet Telescope (LUT) survey program. LUT's observable sky area is a circular belt around the Moon's north pole, and the survey program covers a preferred area for about 2400 square degrees which includes a region of the Galactic plane. All the sources have signal-to-noise ratio larger than 5, and the corresponding magnitude limit is typically 14.4mag, which can be deeper as ~16 mag if the stray light contamination is in the lowest level. A total number of 86,467 stars are recorded in the catalogue.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/479/3509
- Title:
- LVHIS. far-infrared radio correlation
- Short Name:
- J/MNRAS/479/3509
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we measure the far-infrared (FIR) and radio flux densities of a sample of 82 local gas-rich galaxies, including 70 "dwarf" galaxies (M_*_<10^9^M_{sun}_), from the Local Volume HI Survey (LVHIS), which is close to volume limited. It is found that LVHIS galaxies hold a tight linear FIR-radio correlation (FRC) over four orders of magnitude. However, for detected galaxies only, a trend of larger FIR-to-radio ratio with decreasing flux density is observed. We estimate the star formation rate by combining UV and mid-IR data using empirical calibration. It is confirmed that both FIR and radio emission are strongly connected with star formation but with significant non-linearity. Dwarf galaxies are found radiation deficient in both bands, when normalized by star formation rate. It urges a "conspiracy" to keep the FIR-to-radio ratio generally constant. By using partial correlation coefficient in Pearson definition, we identify the key galaxy properties associated with the FIR and radio deficiency. Some major factors, such as stellar mass surface density, will cancel out when taking the ratio between FIR and radio fluxes. The remaining factors, such as HI-to-stellar mass ratio and galaxy size, are expected to cancel each other due to the distribution of galaxies in the parameter space. Such cancellation is probably responsible for the "conspiracy" to keep the FRC alive.
- ID:
- ivo://CDS.VizieR/J/MNRAS/445/881
- Title:
- LVL global optical photometry
- Short Name:
- J/MNRAS/445/881
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the global optical photometry of 246 galaxies in the Local Volume Legacy (LVL) survey. The full volume-limited sample consists of 258 nearby (D<11Mpc) galaxies whose absolute B-band magnitude span a range of -9.6<M_B_<-20.7mag. A composite optical (UBVR) data set is constructed from observed UBVR and Sloan Digital Sky Survey ugriz imaging, where the ugriz magnitudes are transformed into UBVR. We present photometry within three galaxy apertures defined at UV, optical, and IR wavelengths. Flux comparisons between these apertures reveal that the traditional optical R25 galaxy apertures do not fully encompass extended sources. Using the larger IR apertures, we find colour-colour relationships where later type spiral and irregular galaxies tend to be bluer than earlier type galaxies. These data provide the missing optical emission from which future LVL studies can construct the full panchromatic (UV-optical-IR) spectral energy distributions.
- ID:
- ivo://CDS.VizieR/J/MNRAS/445/899
- Title:
- LVL SEDs and physical properties
- Short Name:
- J/MNRAS/445/899
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the panchromatic spectral energy distributions (SEDs) of the Local Volume Legacy (LVL) survey which consists of 258 nearby galaxies (D<11Mpc). The wavelength coverage spans the ultraviolet to the infrared (1500{AA}-24{mu}m) which is utilized to derive global physical properties (i.e. star formation rate, stellar mass, internal extinction due to dust). With these data, we find colour-colour relationships and correlated trends between observed and physical properties (i.e. optical magnitudes and dust properties, optical colour and specific star formation rate, and ultraviolet-infrared colour and metallicity). The SEDs are binned by different galaxy properties to reveal how each property affects the observed shape of these SEDs. In addition, due to the volume-limited nature of LVL, we utilize the dwarf-dominated galaxy sample to test star formation relationships established with higher mass galaxy samples. We find good agreement with the star-forming `main-sequence' relationship, but find a systematic deviation in the infrared `main sequence' at low luminosities. This deviation is attributed to suppressed polycyclic aromatic hydrocarbon (PAH) formation in low-metallicity environments and/or the destruction of PAHs in more intense radiation fields occurring near a suggested threshold in star formation rates (sSFR) at a value of log(sSFR)~-10.2.
- ID:
- ivo://CDS.VizieR/J/ApJ/859/53
- Title:
- Ly{alpha} candidates from a MUSE survey of 6 AGNs
- Short Name:
- J/ApJ/859/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent theoretical models suggest that the early phase of galaxy formation could involve an epoch when galaxies are gas rich but inefficient at forming stars: a "dark galaxy" phase. Here, we report the results of our Multi-Unit Spectroscopic Explorer (MUSE) survey for dark galaxies fluorescently illuminated by quasars at z>3. Compared to previous studies which are based on deep narrowband (NB) imaging, our integral field survey provides a nearly uniform sensitivity coverage over a large volume in redshift space around the quasars as well as full spectral information at each location. Thanks to these unique features, we are able to build control samples at large redshift distances from the quasars using the same data taken under the same conditions. By comparing the rest-frame equivalent width (EW0) distributions of the Ly{alpha} sources detected in proximity to the quasars and in control samples, we detect a clear correlation between the locations of high-EW0 objects and the quasars. This correlation is not seen in other properties, such as Ly{alpha} luminosities or volume overdensities, suggesting the possible fluorescent nature of at least some of these objects. Among these, we find six sources without continuum counterparts and EW0 limits larger than 240{AA} that are the best candidates for dark galaxies in our survey at z>3.5. The volume densities and properties, including inferred gas masses and star formation efficiencies, of these dark galaxy candidates are similar to those of previously detected candidates at z~2.4 in NB surveys. Moreover, if the most distant of these are fluorescently illuminated by the quasar, our results also provide a lower limit of t=60Myr on the quasar lifetime.
- ID:
- ivo://CDS.VizieR/J/A+A/643/A6
- Title:
- Ly{alpha}-[CII] velocity offsets in MS galaxies
- Short Name:
- J/A+A/643/A6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Lyman-{alpha} line in the ultraviolet (UV) and the [CII] line in the far-infrared (FIR) are widely used tools to identify galaxies in the early Universe and to obtain insights into interstellar medium (ISM) properties in high-redshift galaxies. By combining data obtained with ALMA in band 7 at ~320GHz as part of the ALMA Large Program to INvestigate [CII] at Early Times (ALPINE) with spectroscopic data from DEIMOS at the Keck Observatory, VIMOS and FORS2 at the Very Large Telescope, we assembled a unique sample of 53 main-sequence star-forming galaxies at 4.4<z<6 in which we detect both the Lyman-{alpha} line in the UV and the [CII] line in the FIR. The goal of this paper is to constrain the properties of the Ly{alpha} emission in these galaxies in relation to other properties of the ISM. We used [CII], observed with ALMA, as a tracer of the systemic velocity of the galaxies, and we exploited the available optical spectroscopy to obtain the Ly{alpha}-[CII] and ISM-[CII] velocity offsets. We find that 90% of the selected objects have Ly{alpha}-[CII] velocity offsets in the range 0<{Delta}v_Ly{alpha}-[CII]_<400km/s, in line with the few measurements available so far in the early Universe, and significantly smaller than those observed at lower redshifts. At the same time, we observe ISM-[CII] offsets in the range -500<{Delta}v_ISM-[CII]_<0km/s, in line with values at all redshifts, which we interpret as evidence for outflows in these galaxies. We find significant anticorrelations between {Delta}v_Ly{alpha}-[CII]_ and the Ly{alpha} rest-frame equivalent width EW_0_(Ly{alpha}) (or equivalently, the Ly{alpha} escape fraction f_esc_(Ly{alpha})): galaxies that show smaller {Delta}v_Ly{alpha}-[CII]_ have larger EW_0_(Ly{alpha}) and f_esc_(Ly{alpha}). We interpret these results in the framework of available models for the radiative transfer of Ly{alpha} photons. According to the models, the escape of Ly{alpha} photons would be favored in galaxies with high outflow velocities, producing large EW_0_(Ly{alpha}) and small {Delta}v_Ly{alpha}-[CII]_, in agreement with our observations. The uniform shell model would also predict that the Ly{alpha} escape in galaxies with slow outflows (0<v_out_<300km/s) is mainly determined by the neutral hydrogen column density (NHI) along the line of sight, while the alternative model by Steidel et al. (2010ApJ...717..289S) would more highly favor a combination of NHI at the systemic velocity and covering fraction as driver of the Ly{alpha} escape. We suggest that the increase in Ly{alpha} escape that is observed in the literature between z~2 and z~6 is not due to a higher incidence of fast outflows at high redshift, but rather to a decrease in average NHI along the line of sight, or alternatively, a decrease in HI covering fraction.
- ID:
- ivo://CDS.VizieR/J/ApJ/648/7
- Title:
- Ly{alpha} emitters at z=6.5 in Subaru Deep Field
- Short Name:
- J/ApJ/648/7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report an extensive search for Ly{alpha} emitters (LAEs) at z=6.5 in the Subaru Deep Field. Subsequent spectroscopy with Subaru and Keck identified eight more LAEs, giving a total of 17 spectroscopically confirmed LAEs at z=6.5. Based on this spectroscopic sample of 17, complemented by a photometric sample of 58 LAEs, we have derived a more accurate Ly{alpha} luminosity function of LAEs at z=6.5, which reveals an apparent deficit at the bright end of ~0.75mag fainter L*, compared with that observed at z=5.7. The difference in the LAE luminosity functions between z=5.7 and 6.5 is significant at the 3{sigma} level, which is reduced to 2{sigma} when cosmic variance is taken into account. This result may imply that the reionization of the universe has not been completed at z=6.5. We found that the spatial distribution of LAEs at z=6.5 was homogeneous over the field. We discuss the implications of these results for the reionization of the universe.
- ID:
- ivo://CDS.VizieR/J/PASJ/57/165
- Title:
- Ly{alpha} emitters in the SUBARU Deep Field
- Short Name:
- J/PASJ/57/165
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new results of a deep optical imaging survey using a narrow band filter (NB921) centered at {lambda}=9196{AA} together with B, V, R, i', and z' broadband filters in the sky area of the Subaru Deep Field, which has been promoted as one of legacy programs of the 8.2m Subaru Telescope. We obtained a photometric sample of 58 Ly{alpha} emitter candidates at z~6.5-6.6 among ~180 strong NB921-excess (z'-NB921>1.0) objects together with a color criterion of i'-z'>1.3. We then obtained optical spectra of 20 objects in our NB921-excess sample, and identified at least nine Ly{alpha} emitters at z~6.5-6.6, including the two emitters reported by Kodaira et al. (2003PASJ...55L..17K). Since our Ly{alpha}-emitter candidates are free from strong amplification of gravitational lensing, we are able to discuss their observational properties from a statistical point of view. Based on these new results, we obtained a lower limit of the star-formation rate density of rho_SFR_~5.7x10^-4^h_0.7_M_{sun}/yr/Mpc^3^ at z~6.6, being consistent with our previous estimate. We discuss the nature of star-formation activity in galaxies beyond z=6.
- ID:
- ivo://CDS.VizieR/J/PASJ/58/313
- Title:
- Ly{alpha} emitters in the SUBARU Deep Field
- Short Name:
- J/PASJ/58/313
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the properties of Ly{alpha} emitters (LAEs) at z=5.7 in the Subaru Deep Field. A photometric sample of 89 LAE candidates was constructed from narrow-band data down to NB816=26.0 (AB) in a continuous 725arcmin^2^ area. Spectra of 39 objects satisfying the photometric selection criteria for LAEs were obtained with Subaru and Keck II Telescopes, among which 28 were confirmed LAEs, one was a nearby galaxy, and eight were unclassified. We also obtained spectra of another 24 NB816-excess objects in the field, identifying six additional LAEs.
- ID:
- ivo://CDS.VizieR/J/A+A/498/13
- Title:
- Lyman-{alpha} emitters from redshifts z~2-3
- Short Name:
- J/A+A/498/13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Narrow-band surveys to detect Ly{alpha} emitters are powerful tools for identifying high, and very high, redshift galaxies. Although samples are increasing at redshifts z=3-6, the nature of these galaxies is still poorly known. The number of galaxies detected at redshifts below z~3 are also small. We study the properties of z=2.25 Ly{alpha} emitters and compare them with those of z>3 Ly{alpha} emitters We present narrow-band imaging made with the MPG/ESO 2.2m telescope and the WFI (Wide Field Imager) detector. Using this data, we have searched for emission-line objects. We find 170 candidate typical Ly{alpha} emitters and 17 candidates that we regard as high UV-transmission Ly{alpha} emitters. We have derived the magnitudes of these objects in 8 photometric bands from u* to K_s_, and studied whether they have X-ray and/or radio counterparts.
