Near-infrared Mira period-luminosity relations in M33
Short Name:
J/AJ/156/112
Date:
21 Oct 2021
Publisher:
CDS
Description:
We analyze sparsely sampled near-infrared (JHK_s_) light curves of a sample of 1781 Mira variable candidates in M33, originally discovered using I-band time-series observations. We extend our single-band semi-parametric Gaussian process modeling of Mira light curves to a multiband version and obtain improved period determinations. We use our previous results on near-infrared properties of candidate Miras in the LMC to classify the majority of the M33 sample into oxygen- or carbon-rich subsets. We derive period-luminosity relations for O-rich Miras and determine a distance modulus for M33 of 24.80+/-0.06 mag.
We determine probabilities of physical association for stars in blended Kepler Objects of Interest (KOIs), and find that 14.5%_-3.4%_^+3.8%^ of companions within ~4'' are consistent with being physically unassociated with their primary. This produces a better understanding of potential false positives in the Kepler catalog and will guide models of planet formation in binary systems. Physical association is determined through two methods of calculating multi-band photometric parallax using visible and near-infrared adaptive optics observations of 84 KOI systems with 104 contaminating companions within ~4''. We find no evidence that KOI companions with separations of less than 1'' are more likely to be physically associated than KOI companions generally. We also reinterpret transit depths for 94 planet candidates, and calculate that 2.6%+/-0.4% of transits have R>15R_{oplus}_, which is consistent with prior modeling work.
Near-infrared, JHKL, photometry of 239 Galactic C-rich variable stars is presented and discussed. From these and published data, the stars were classified as Mira or non-Mira variables, and amplitudes and pulsation periods, ranging from 222 to 948d for the Miras, were determined for most of them. A comparison of the colour and period relations with those of similar stars in the Large Magellanic Cloud indicates minor differences, which may be the consequence of sample selection effects. Apparent bolometric magnitudes were determined by combining the mean JHKL fluxes with mid-infrared photometry from IRAS and MSX.
We have carried out near-infrared (NIR) imaging observations of the Carina Nebula for an area of ~400arcmin^29 including the clusters Trumpler 14 and Trumpler 16, with 10sigma limits of J~18.5, H~17.5, and Ks ~16.5mag. A total of 544 Class II candidates, 11 Class I candidates, and 40 red (H-Ks>2) sources have been found.
We have conducted aperture polarimetry of ~500 stars of the Orion Nebula Cluster in M42 based on our wide-field (~8'x8') JHKs-band polarimetry. Most of the near-infrared (NIR) polarizations are dichroic, with position angles of polarization agreeing, both globally and locally, with previous far-infrared (FIR) and submillimeter observations, having taken into account the 90{deg} difference in angles between dichroic absorption and emission. This is consistent with the idea that both NIR dichroic polarizations and FIR/submillimeter thermal polarizations trace the magnetic fields in the OMC-1 region.
We present the result of a deep near-infrared survey of the newly identified X-ray luminous cluster of galaxies CIZA J1324.7-5736 in the Great Attractor (GA) region. In a 35x35arcmin^2^ region, 111 galaxy candidates with r(Ks20)>3arcsec are identified.
The highly obscured radio-bright galaxy PKS 1343-601 at Galactic coordinates of (l,b)=(309.7,+1.8) has been suspected to mark the centre of a hitherto unknown cluster in the wider Great Attractor region. As such it presents an ideal region for a search of galaxies in the near-infrared (NIR) and an in-depth study of their colours as a function of extinction. A visual search of a ~30 square-degree area centred on this radio galaxy on images of the NIR DENIS survey (IJK) revealed 83 galaxies (including two AGNs) and 39 possible candidates. Of these, 49 are also listed in the 2MASS Extended Source Catalog 2MASX. Taking the IRAS/DIRBE extinction values (Schlegel et al., 1998ApJ...500..525S) at face value, the absorption in the optical (AB) ranges from ~2mag to over 100mag across the Galactic Plane. Comparing the detections with other systematic surveys, we conclude that this search is highly complete up to the detection limits of the DENIS survey and certainly surpasses any automatic galaxy finding algorithm applied to crowded areas.
We present the results of a deep near-infrared survey of a 36x36arcmin^2^ region centred on the giant elliptical radio galaxy PKS 1343-601, suggested to be the core of an unknown rich cluster located at the low Galactic latitude of b=1.73{deg} in the Great Attractor (GA) region. 19 obvious galaxies and 38 galaxy candidates have been detected; only three of them were previously identified as a galaxy.
We conducted wide-field near-infrared imaging observations of 32 bright rimmed clouds (BRCs). Given a detection limit of 17.7mag at the K-band, we identified 2099 objects as young stellar object (YSO) candidates that displayed near-infrared excesses. Their masses, estimated from luminosities, range from 0.006M_{sun}_ to 2.7M_{sun}_. The candidates are not uniformly distributed. For 21 BRCs, more than half of the associated YSO candidates are located inside the cloud. We found clear evidence of triggered star formation. The number of YSO candidates is not correlated with the core mass of the molecular clouds. Instead, the YSO number increases with increasing UV photon flux from the exciting star illuminating the cloud surface. UV radiation activates star formation in the BRCs.
We report the results of a near-infrared survey for long-period variables in a field of view of 20x30arcmin^2^ towards the Galactic Centre (GC). We have detected 1364 variables, of which 348 are identified with those reported in Glass et al. (2001. Cat. <J/MNRAS/321/77>). We present a catalogue and photometric measurements for the detected variables and discuss their nature.
