The Influence of Outflow Feedback in Clumps Li, Qiang; Li, Mingyue; Zhang, Li ...
Astrophysical journal/The Astrophysical journal,
10/2023, Letnik:
956, Številka:
1
Journal Article
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Abstract
We analyzed the influence of outflow feedback from two perspectives: turbulent support and potential disruptive effect, of which 694 clumps and 188 have been identified as outflow ...candidates. For turbulent support, we find the slopes of
E
turb
−
R
clump
(turbulent energy and radius of the clump) and
P
turb
−
R
clump
(turbulent momentum and radius of the clump) have no difference and are consistent with expected values whether there is outflow feedback in clumps or not. The ratios of the outflow energy and momentum to the turbulence energy and momentum (
E
flow
/
E
turb
,
P
flow
/
P
turb
) show that the majority of clumps have not enough energy and momentum to support turbulence. Meanwhile, there is no correlation between the velocity dispersion and radius. For potential disruptive effects, we conclude that it is impossible for the outflow activities to disrupt entire clumps and as the mass of the clumps increases, the clumps becomes harder to destroy. Finally, we do not see evidence that the virial parameter changes significantly whether the clumps have outflow candidates or not.
Abstract
We study the magnetic field structures in six giant filaments associated with the spiral arms of the Milky Way by applying the velocity gradient technique (VGT) to the
13
CO spectroscopic ...data from the GRS, FUGIN, and SEDIGSM surveys. Unlike dust-polarized emission, the VGT allows us to separate the foreground and background using the velocity information, from which the orientation of the magnetic field can be reliably determined. We find that in most cases the magnetic fields stay aligned with the filament bodies, which are parallel to the disk midplane. Among these, G29, G47, and G51 exhibit smooth magnetic fields, and G24, G339, and G349 exhibit discontinuities. The fact that most filaments have magnetic fields that stay aligned with the Galactic disk midplane suggests that Galactic shear may be responsible for shaping the filaments. The fact that the magnetic field can stay regular at the resolution of our analysis (≲10 pc), where the turbulence crossing time is short compared to the shear time, suggests that turbulent motion cannot effectively disrupt the regular orientation of the magnetic field. The discontinuities found in some filaments can be caused by processes including filament reassembly, gravitational collapse, and stellar feedback.
Abstract We report the detection of the ordered alignment between the magnetic field and kpc-scale bubbles in the nearby spiral galaxy, NGC 628. Applying the Velocity Gradient Technique on CO ...spectroscopic data from the ALMA-PHANGS, the magnetic field of NGC 628 is measured at the scale of 191 pc (∼4″). The large-scale magnetic field is oriented parallel to the spiral arms and curves around the galactic bubble structures in the mid-infrared emission observed by the James Webb Space Telescope. A total of 21 bubble structures have been identified at the edges of spiral arms with scales over 300 pc, which includes two kpc-scale structures. These bubbles are caused by supernova remnants and prolonged star formation and are similar to the outflow chimneys found in neutral hydrogen in galactic disks. At the edge of the bubbles, the shocks traced by the O iii emission present a curved magnetic field that parallels the bubble’s shell. The magnetic field follows the bubble expansion and binds the gas in the shell to trigger further star formation. By analyzing the larger sample of 1694 bubbles, we found a distinct radial-size distribution of bubbles in NGC 628 indicating the star formation history in the galaxy.
We select 13 nearby spiral galaxies from the Nearby Galaxies Legacy Survey (NGLS) project and perform spectral energy distribution fitting for each galaxy applying two-component modified blackbody ...models on a global scale aim to probe the potential submillimeter (submm) excess. We find that NGC 2976, NGC 3351, and NGC 4631 show excess emission at 850 m when using βc = 2.0. The contributions of CO(3-2), free-free emission or synchrotron radiation cannot explain their 850 m excess. Our results suggest that a submm excess at 850 m may be more easily detected for galaxies with faint total infrared luminosity and low cold dust mass. The colder temperature of cold dust, the more radiation of dust there is at 850 m. The submm excess are prone to be detected in spiral galaxies with low stellar mass. As the metallicity of galaxies become poor, the submm excess is more obvious.
Abstract
Combining infrared and submillimeter observations and applying a two-temperature modified blackbody (TMBB) model with a hierarchical Bayesian technique, we model the spectral energy ...distribution of 12 nearby dwarf irregular (dIrr) galaxies. We aim to probe potential submillimeter excess emission at 350, 500, and 850
μ
m and investigate the properties of cold dust parameters. Based on the TMBB model with cold dust emissivity index (
β
c
) fixed to 2, one galaxy shows 500
μ
m excess emission and nine galaxies show excess at 850
μ
m (five of them still show 850
μ
m excess in the case of free
β
c
). We find that the 850
μ
m excess emission is easily detected in the dIrr galaxies with low star formation activity. The 850
μ
m excess is more frequent and more prominent in dIrr galaxies with low molecular hydrogen gas mass fraction or low ratios between cold dust mass and gas mass. As galaxies evolve, the ratios between atomic hydrogen gas mass and stellar mass decrease and the 850
μ
m excess emission tends to decrease or even disappear. Our results suggest that the cold dust temperature may increase, as the dIrr galaxies have more intense star formation or richer metallicity. There is a weak anticorrelation between the cold dust-to-stellar mass ratio and the specific star formation rate for our galaxies.
We report the detection of the ordered alignment between the magnetic field and kpc-scale bubbles in the nearby spiral galaxy, NGC\,628. Applying the Velocity Gradient Technique (VGT) on CO ...spectroscopic data from the ALMA-PHANGS, the magnetic field of NGC\,628 is measured at the scale of 191\,pc (\(\sim\) 4\,\(''\)). The large-scale magnetic field is oriented parallel to the spiral arms and curves around the galactic bubble structures in the mid-infrared emission observed by the James Webb Space Telescope (JWST). Twenty-one bubble structures have been identified at the edges of spiral arms with scales over 300\,pc, which includes two kpc-scale structures. These bubbles are caused by supernova remnants and prolonged star formation and are similar to the outflow chimneys found in neutral hydrogen in galactic disks. At the edge of the bubbles, the shocks traced by the OIII emission present a curved magnetic field that parallels the bubble's shell. The magnetic field follows the bubble expansion and binds the gas in the shell to trigger further star formation. By analyzing the larger sample of 1694 bubbles, we found a distinct radial-size distribution of bubbles in NGC\,628 indicating the star formation history in the galaxy.
We study the magnetic field structures in six giant filaments associated with the spiral arms of the Milky Way by applying the Velocity Gradient technique (VGT) to the 13CO spectroscopic data from ...GRS, Fugin, and SEDIGSM surveys. Compared to dust polarized emission, the VGT allows us to separate the foreground and background using the velocity information, from which the orientation of the magnetic field can be reliably determined. We find that in most cases, the magnetic fields stay aligned with the filament bodies, which are parallel to the disk midplane. Among these, G29, G47, and G51 exhibit smooth magnetic fields, and G24, G339, and G349 exhibit discontinuities. The fact that most filaments have magnetic fields that stay aligned with the Galactic disk midplane suggests that Galactic shear can be responsible for shaping the filaments. The fact that the magnetic field can stay regular at the resolution of our analysis (<= 10 pc) where the turbulence crossing time is short compared to the shear time suggests that turbulent motion can not effectively disrupt the regular orientation of the magnetic field. The discontinuities found in some filaments can be caused by processes including filament reassembly, gravitational collapse, and stellar feedback.
The combination of phytochemicals with chemotherapy drugs is an emerging new strategy for cancer therapy to increase antitumor responses.
The present study investigates the effect of the combination ...of capsaicin (CAP) with cisplatin (DDP) and the potential underlying anticancer mechanisms in osteosarcoma (OS) cells in vitro and in vivo.
Cell viability assays and isobolographic analyses demonstrated that the combination of CAP and DDP showed synergistic cytotoxic effects on OS cells. We chose relatively low concentrations of CAP (100 μM) and DDP (16.7 μM) for subsequent experiments. Generally, the combination of CAP and DDP had significant effects on apoptosis induction, cell cycle arrest and cell invasion inhibition in OS cells compared with the individual-treatment groups and the control group. Moreover, cotreatment with CAP and DDP triggered prosurvival autophagy through reactive oxygen species (ROS)/JNK and p-AKT/mTOR signaling in OS cells. The combination regimen of CAP and DDP also inhibited tumor growth in an OS xenograft model.
These results suggest that the combination of CAP and DDP has strong inhibitory effects on OS cells and identify CAP as a promising agent for supplementing standard chemotherapy and possible future targeted therapy in OS.
The tumor margin as the invasive front has been proven to be closely related to the progression and metastasis of oral squamous cell carcinoma (OSCC). However, how tumor cells in the marginal region ...obtain the extra energy needed for tumor progression is still unknown. Here, we used spatial metabolomics and the spatial transcriptome to identify enhanced energy metabolism in the tumor margin of OSCC and identified that the downregulation of Ras-related glycolysis inhibitor and calcium channel regulator (RRAD) in tumor cells mediated this process. The absence of RRAD enhanced the ingestion of glucose and malignant behaviors of tumor cells both in vivo and in vitro. Mechanically, the downregulation of RRAD promoted the internal flow of Ca
and elevated its concentration in the nucleus, which resulted in the activation of the CAMKIV-CREB1 axis to induce the transcription of the glucose transporter GLUT3. GLUT inhibitor-1, as an inhibitor of GLUT3, could suppress this vigorous energy metabolism and malignant behaviors caused by the downregulation of RRAD. Taken together, our study revealed that enhanced energy metabolism in the tumor margin mediated by RRAD promotes the progression of OSCC and proved that GLUT3 is a potential target for future treatment of OSCC.
Climate change is a prominent factor reshaping the distribution of invasive species. Metcalfa pruinosa (Say 1830) (Hemiptera: Flatidae), native to North America, has invaded other continents and ...poses a serious threat to various agricultural crops and the human residential environment. Understanding the distribution of M. pruinosa based on climatic conditions is a critical first step to prevent its further invasion. Therefore, based on its occurrence records and associated environmental variables, a Maxent model was developed to predict suitable areas for this species in the present and future on a global scale. The model exhibited outstanding performance, with a mean area under the receiver operating characteristic curve and true skill statistic values of 0.9329 and 0.926, respectively. The model also indicated that annual precipitation (Bio12) and max temperature of the warmest month (Bio5) were the key environmental variables limiting the distribution of M. pruinosa. Moreover, the model revealed that the current suitable area is 1.01 × 107 km2 worldwide, with southern China, southern Europe, and the eastern United States predicted to be the primary and highly suitable areas in the latter 2 regions. This area is expected to increase under future climate scenarios, mainly in the northern direction. The study's findings contribute to our understanding of climate change's impact on M. pruinosa distribution, and they will aid governments in developing appropriate pest management strategies, including global monitoring and strict quarantine measures.
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