The Purple Mountain Observatory 13.7 m radio telescope has been used to search for 95 GHz (8₀–7₁A⁺) class I methanol masers toward 1020 Bolocam Galactic Plane Survey (BGPS) sources, leading to 213 detections. We have compared the line width of the methanol and HCO⁺ thermal emission in all of the methanol detections, and on that basis, we find that 205 of the 213 detections are very likely to be masers. This corresponds to an overall detection rate of 95 GHz methanol masers toward our BGPS sample of 20%. Of the 205 detected masers, 144 (70%) are new discoveries. Combining our results with those of previous 95 GHz methanol maser searches, a total of 481 95 GHz methanol masers are now known. We have compiled a catalog listing the locations and properties of all known 95 GHz methanol masers.

We present a survey of molecular outflows across the dark cloud complex in the Cygnus region, based on a 46.75 deg² field of CO isotopologue data from the Milky Way Imaging Scroll Painting survey. A supervised machine-learning algorithm, the support vector machine, is introduced to accelerate our visual assessment of outflow features in the data cube of ¹²CO and ¹³CO J = 1−0 emission. A total of 130 outflow candidates are identified, 77 of which show bipolar structures and 118 are new detections. Spatially, these outflows are located inside dense molecular clouds, and some of them are found in clusters or in elongated linear structures tracing the underlying gas filament morphology. Along the line of sight, 97, 31, and 2 candidates reside in the Local, Perseus, and Outer Arms, respectively. Young stellar objects as outflow drivers are found near most outflows, while 36 candidates show no associated source. The clusters of outflows that we detect are inhomogeneous in their properties; nevertheless, we show that the outflows cannot inject turbulent energy on cloud scales. Instead, at best, they are restricted to affecting the so-called “clump” and “core” scales, and only on short (∼0.3 Myr) estimated timescales. Combined with outflow samples in the literature, our work shows a tight outflow mass–size correlation.

We present the first data release (DR1) of the Milky Way Imaging Scroll Painting (MWISP) survey, a mapping in the J = 1 → 0 transition lines of ¹² CO, ¹³ CO, and C ¹⁸ O toward the northern Galactic plane during 2011–2022. The MWISP survey was conducted using the Purple Mountain Observatory 13.7 m telescope at a spatial resolution of approximately 50″ and a velocity resolution of 0.16 km s ⁻¹ at 115 GHz. DR1 fully covered 2310 deg ² within the Galactic longitude ( l ) and latitude ( b ) range of 9 . ° 75 ≤ l ≤ 229 . ° 75 and ∣ b ∣ ≤ 5 . ° 25. The surveyed area was divided into cell units of 30 ′ × 30 ′ for practical purposes and on-the-fly mapping was performed toward each target cell unit. The data were regridded into a regular three-dimensional data cube in l – b – V _LSR with a pixel size of 30″ in l – b axes and 0.16 km s ⁻¹ in the V _LSR axis. The median rms noise is 0.47, 0.25, and 0.25 K for ¹² CO, ¹³ CO, and C ¹⁸ O, respectively. The equivalent 3 σ sensitivity in ¹² CO luminosity is approximately 0.23 K km s ⁻¹ , making MWISP the most sensitive survey of its kind. In this paper, we describe the survey data, including the calibration, data cleaning, data mosaic processes, and the data products. The final mosaicked data cubes contain about 3.33 × 10 ⁷ spectra (pixels) for each CO isotopologue line. Color composite images, made from the intensities of the isotopologue lines, and some concise descriptions are provided. We constructed a molecular cloud catalog based on the mosaicked ¹² CO data cube using the clustering algorithm DBSCAN, detecting 103,517 molecular clouds, 10,790 of which exhibit ¹³ CO emission and 304 of which show C ¹⁸ O emission. Based on the histogram of voxel brightness temperature, we estimated a total ¹² CO flux of 7.69 ± 0.38 × 10 ⁷ K km s ⁻¹ arcmin ² , 82% of which is captured by the DBSCAN algorithm. The properties of molecular clouds show a large dynamic range, facilitating more accurate statistics. The data, together with the cloud sample, provide unique information on molecular gas in the northern Milky Way.

We present the results of an unbiased ¹²CO/¹³CO/C¹⁸O (J = 1–0) survey in a portion of the third Galactic quadrant (TGQ): 219.°75 ≤ l ≤ 229.°75 and −5.°25 ≤ b ≤ 5.°25. The high-resolution and high-sensitivity data sets help to unravel the distributions and physical properties of the molecular clouds (MCs) in the mapped area. In the LSR velocity range from ∼−1 to ∼85 km s⁻¹, the molecular material successfully traces the Local, Perseus, and Outer arms. In the TGQ, the Outer arm appears to be more prominent than that in the second Galactic quadrant (SGQ), but the Perseus arm is not as conspicuous as that in the SGQ. A total of 1,502 ¹²CO, 570 ¹³CO, and 53 C¹⁸O molecular structures are identified, spanning over ∼2 and ∼6 orders of magnitude in size and mass, respectively. Tight mass–radius correlations and virial parameter–mass anticorrelations are observable. Yet, it seems that no clear correlations between velocity dispersion and effective radius can be found over the full dynamic range. The vertical distribution of the MCs renders evident pictures of the Galactic warp and flare.

We measured the relative positions between two pairs of compact extragalactic sources (CESs), J1925-2219 and J1923-2104 (C1–C2) and J1925-2219 and J1928-2035 (C1–C3), on 2020 October 23–25 and 2021 February 5 (totaling four epochs), respectively, using the Very Long Baseline Array at 15 GHz. Accounting for the deflection angle dominated by Jupiter, as well as the contributions from the Sun and planets other than Earth, the Moon, and Ganymede (the most massive of the solar system’s moons), our theoretical calculations predict that the dynamical ranges of the relative positions across four epochs in R.A. of the C1–C2 pair and C1–C3 pair are 841.2 and 1127.9 μas, respectively. The formal accuracy in R.A. is about 20 μas, but the error in decl. is poor. The measured standard deviations of the relative positions across the four epochs are 51.0 and 29.7 μas in R.A. for C1–C2 and C1–C3, respectively. These values indicate that the accuracy of the post-Newtonian relativistic parameter, γ, is ∼0.061 for C1–C2 and ∼0.026 for C1–C3. Combining the two CES pairs, the measured value of γ is 0.984 ± 0.037, which is comparable to the latest published results for Jupiter as a gravitational lens, reported by Fomalont & Kopeikin, i.e., 1.01 ± 0.03.

We present a large-scale survey of CO outflows in the Gem OB1 molecular cloud complex and its surroundings, using the Purple Mountain Observatory Delingha 13.7 m telescope. A total of 198 outflow candidates were identified over a large area (∼58.5 square degrees), of which 193 are newly detected. Approximately 68% (134/198) are associated with the Gem OB1 molecular cloud complex, including clouds GGMC 1, GGMC 2, BFS 52, GGMC 3, and GGMC 4. Other regions studied are: the Local arm (Local Lynds, West Front), Swallow, Horn, and Remote cloud. Outflow candidates in GGMC 1, BFS 52, and Swallow are mainly located at ring-like or filamentary structures. To avoid excessive uncertainty in distant regions (≳3.8 kpc), we only estimated the physical parameters for clouds in the Gem OB1 molecular cloud complex and in the Local arm. In those clouds, the total kinetic energy and the energy injection rate of the identified outflow candidates are ≲1% and ≲3% of the turbulent energy and the turbulent dissipation rate of each cloud, indicating that the identified outflow candidates cannot provide enough energy to balance turbulence of their host cloud at the scale of the entire cloud (several to dozens of parsecs). The gravitational binding energy of each cloud is ≳135 times the total kinetic energy of the identified outflow candidates within the corresponding cloud, indicating that the identified outflow candidates cannot cause major disruptions to the integrity of their host cloud at the scale of the entire cloud.