What Kinds of Accretion Disks Are There in the Nuclei of Radio Galaxies?

It seems to be a widely accepted opinion that the types of accretion disks (or flows) generally realized in the nuclei of radio galaxies and in further lower mass-accretion rate nuclei are inner, hot, optically thin, radiatively inefficient accretion flows (RIAFs) surrounded by outer, cool, optically thick, standard type accretion disks. However, observational evidence for the existence of such outer cool disks in these nuclei is rather poor. Instead, recent observations sometimes suggest the existence of inner cool disks of non-standard type, which develop in the region very close to their central black holes. Taking NGC 4261 as a typical example of such light eating nuclei, for which both flux data ranging from radio to X-ray and data for the counterjet occultation are available, we examine the plausibility of such a picture for the accretion states as mentioned above, based on model predictions. It is shown that the explanation of the gap seen in the counterjet emission in terms of the free-free absorption by an outer standard disk is unrealistic, and moreover, the existence itself of such an outer standard disk seems very implausible. Instead, the model of RIAF in an ordered magnetic field (so called resistive RIAF model) can well serve to explain the emission gap in terms of the synchrotron absorption, as well as to reproduce the observed features of the overall spectral energy distribution (SED). This model also predicts that the RIAF state starts directly from an interstellar hot gas phase at around the Bondi radius and terminates at the inner edge whose radius is about 100 times the Schwartzschild radii. Therefore, there is a good possibility for a cool disk to develop within this innermost region.Comment: 8 pages, 3 figures, to appear in PASJ, Vol.62, No.

Surgery did not improve the subjective neuropsychological symptoms of patients with incidentally detected mild primary hyperparathyroidism

Primary hyperparathyroidism (PHPT) is known to cause diverse subjective symptoms, in addition to those related to osteitis fibrosa cystica and kidney stones. The treatment of the disease ameliorates the subjective symptoms and improves the patients’ quality of life. In this prospective study, patients undergoing surgery for incidentally detected, mild, asymptomatic PHPT were assessed to determine whether subjective neuropsychological symptoms are improved even in patients with “asymptomatic” PHPT. From October 1995 to March 2004, 25 patients who had one or more neuropsychological symptoms preoperatively and were followed up 1 year after parathyroidectomy were enrolled. The subjective symptoms were identified using questionnaires distributed to patients; eight questions were used to determine the presence or absence of psychoneurological symptoms. Compared to their preoperative status, patients responded that their general health perceptions 1 year after surgery were improved (13 cases, 52%), unchanged (11 cases, 44%), or aggravated (1 case, 4%). There were no statistically significant differences in the patients’ responses before and after surgery with respect to individual neuropsychological symptoms, such as “tiring easily, “forgetfulness,” “decreased concentration,” “depression,” “irritability,” “uneasiness,” and “sleeplessness.” Therefore, subjective neuropsychological symptoms did not improve in otherwise asymptomatic PHPT patients following parathyroidectomy. However, patients’ questionnaire responses may not reflect their actual status as accurately as laboratory examination results. Overall, 52% of patients were subjectively satisfied with surgery; this may result from patients’ expectations of treatment

Internal Motion of 6.7-GHz Methanol Masers in H II Region S269

We present the first internal motion measurement of the 6.7-GHz methanol maser within S269, a small HII region in the outer Galaxy, which was carried out in 2006 and 2011 using the Japanese VLBI Network (JVN). Several maser groups and weak isolated spots were detected in an area spanning by ~200 mas (1000 AU). Three remarkable maser groups are aligned at a position angle of 80 degree. Two of three maser groups were also detected by a previous observation in 1998, which allowed us to study a long-term position variation of maser spots from 1998 to 2011. The angular separation between the two groups increased ~10 mas, which corresponds to an expansion velocity of ~10 km s^{-1}. Some velocity gradient (~10^{-2} km s^{-1} mas^{-1}) in the overall distribution was found. The internal motion between the maser groups support the hypothesis that the methanol masers in S269 could trace a bipolar outflow.Comment: 8 pages, 6 figures, accepted for publication in PAS

Constraints on the dust size distributions in the HD 163296 disk from the difference of the apparent dust ring widths between two ALMA Bands

The dust size in protoplanetary disks is a crucial parameter for understanding planet formation, while the observational constraints on dust size distribution have large uncertainties. In this study, we present a new method to constrain the dust size distribution from the dust spatial distribution, utilizing the fact that larger dust grains are more spatially localized. We analyze the ALMA Band 6 (1.25 mm) and Band 4 (2.14 mm) high-resolution images and constrain the dust size distribution in the two rings of the HD 163296 disk. We find that the outer ring at 100 au appears narrower at the longer wavelengths, while the inner ring at 67 au appears to have similar widths across the two wavelengths. We model dust rings trapped at gas pressure maxima, where the dust grains follow a power-law size distribution, and the dust grains of a specific size follow a Gaussian spatial distribution with the width depending on the grain size. By comparing the observations with the models, we constrain the maximum dust size $a_{\mathrm{max}}$ and the exponent of the dust size distribution $p$. We constrain that $0.9 \ \mathrm{mm} < a_{\mathrm{max}} < 5 \ \mathrm{mm}$ and $p 3 \times 10^1 \ \mathrm{mm}$ and $3.4 < p < 3.7$ in the outer ring. The larger maximum dust size in the outer ring implies a spatial dependency in dust growth, potentially influencing the formation location of the planetesimals. We further discuss the turbulence strength $\alpha$ derived from the constrained dust spatial distribution, assuming equilibrium between turbulent diffusion and accumulation of dust grains.Comment: 29 pages, 16 figures. Accepted for publication in Ap

Growth curve of the body weight, body length and tail length in the cotton rat (Sigmodon hispidus)

The body weight (BW), body length (BL) and tail length (TL) of 202 cotton rats, 102 males and 100 females. were measured. Significant sex differences in the BW were observed 3 weeks after birth. The BLs in one-day-old males and females were 8.33 = 0.36 cm and 7.82 +/- 0.69 cm respectively, while the TLs were 2.98 +/- 0.12 cm and 2.88 + 0.28 cm. Growth of the BL and TL was rapid until about 8th week of age, when a steady length was reached. The equations in males were BL (em) = 8.07 + 0.23 x BW (g) - 0.00068 x BW (g)2, TL (em) = 2.79 + 0.11 x BW (g) -0.00037 x BW (g)2 and TL (cm) = — 2.21 + 0.67 x BL (em) — 0.0068 &gt;&lt; BL (cm)2. Correlations among the BW, BL and TL in male and female cotton rats were all highly significant (r 20.98, P &lt; 0.001)